It is not so much a difference of dogma that turns the hearts of the Greeks against you as the hatred of the Latins which has entered into their spirit, in consequence of the many and great evils which the Greeks have suffered from the Latins at various times, and are still suffering day by day.
Barlaam of Calabria to Pope Benedict XII, c.1340
In contrast to Doge Dandolo, who now proudly styled himself 'Lord of a Quarter and Half a Quarter of the Roman Empire', the Emperor Baldwin I cut a sorry figure. When another three-eighths of the Empire had been parcelled out among the Frankish knights as imperial fiefs, he was left with just a quarter of the territory that had been ruled by his immediate predecessors. Essentially it comprised Thrace — though not of course Adrianople, which had gone to the Venetians - and the northwest region of Asia Minor, together with certain islands of the Aegean including Lesbos, Samos and Chios; but even this pathetically diminished patrimony was contested. Boniface of Montferrat in particular, who had been virtually certain of the throne and was furious at having been passed over, angrily refused the Anatolian lands he was offered and instead seized Thessalonica, where he established a kingdom extending over a large part of Macedonia and Thessaly. Somehow, too, he managed to assume the suzerainty over the lesser Frankish rulers springing up to the south, notably the Burgundian Otto de la Roche in Boeotia and Attica (the so-called Duchy of Athens) and the Frenchman William of Champlitte - soon to be succeeded by the house of Villehardouin - in the Peloponnese.
It comes as no surprise to learn that the new rulers were detested throughout these formerly Byzantine lands. Economically there were few major changes: apart from the fact that taxes were henceforth paid to a Latin landlord rather than to a Greek, provincial and country life probably continued much as it had always done. Morally and spiritually,
however, the climate was entirely altered. Not only were the Franks overbearing and arrogant, making no effort to conceal their scorn for what they considered an inferior as well as a subject race; they were also staunch upholders of the Church of Rome, and unhesitatingly imposed the Latin rite wherever they could. For the local proletariat and the peasantry there was little to be done; sullenly, resentfully and with bitterness in their hearts, they accepted the inevitable. The aristocracy, on the other hand, was a good deal less submissive; many Greek nobles left their ancestral lands in disgust and moved to one of the Byzantine successor states in which the national spirit and the Orthodox faith were still preserved.
Of these states, the largest, the most powerful and by far the most important was the so-called Empire of Nicaea, of which Alexius Ill's son-in-law Theodore Lascaris was recognized as Emperor in 1206, being crowned there two years later. It occupied a broad strip of land at the western extremity of Anatolia, averaging some two hundred miles across and extending from the Aegean to the Black Sea coast. To the north and west lay the Latin Empire; to the south and east, the Seljuk Sultanate. Although the official capital remained Nicaea - which after 1208 was the seat of the Patriarch and where all the imperial coronations took place -Theodore's successor John III Vatatzes was to establish his chief residence in the Lydian city of Nymphaeum (now Kemalpasa) which was far better placed from the strategic point of view; and for most of the fifty-seven-year period of exile from Constantinople it was from here rather than from Nicaea that the Empire was effectively governed.
The two other successor states were less important. Situated as they were, one on the Adriatic coast and the other at the south-eastern extremity of the Black Sea, they were too remote to exert much influence on the march of events; nor could they ever boast the special prestige which the presence of the Patriarchate conferred upon Nicaea. The Despotate of Epirus (to use its later title) was founded soon after the capture of Constantinople by a certain Michael Comnenus Ducas, the illegitimate son of the sebastocrator John Angelus Ducas (grandson of Alexius I Comnenus through his daughter Theodora) and thus a cousin of Isaac II and Alexius III, although - not altogether surprisingly -neither he nor his father ever used the name of Angelus themselves. From his capital at Arta he established control over the entire northwestern coast of Greece and part of Thessaly - a domain which was soon to be substantially increased by his half-brother Theodore who, succeeding him in 1215, captured Thessalonica from the Latins nine years later and promptly had himself crowned Emperor as a rival to John Vatatzes of Nicaea. This rivalry, however, did not last long: in 1242 Vatatzes obliged Theodore's son John to renounce the imperial title in favour of that of despotes, and four years later he appropriated Thessalonica for himself.
Unlike Nicaea and Epirus, the Empire of Trebizond was not the result of the fall of Constantinople. Indeed, it had been founded in April 1204 - within days of the disaster - by Alexius and David Comnenus, grandsons of the Emperor Andronicus through his son Manuel, who had married a Georgian princess. After the fall of Andronicus in 1185 the young brothers had been taken for safety to Georgia, where they had been brought up at the royal court. Determined to continue the Comnenus dynasty in opposition to the Angeli, they had captured Trebizond -with the help of the Georgian Queen Thamar - in April 1204. Later in the same year David had pushed west along the Black Sea coast with his army of Georgians and other mercenaries to occupy Paphlagonia as far as Heraclea; but much of this territory was lost soon afterwards, and for the greater part of its 257-year history - for it was to continue after the recovery of Constantinople and did not ultimately fall to the Turks until 1461 — the Trapezuntine Empire was confined to a narrow strip of coastline rather less than four hundred miles long between the Pontic mountains and the sea.
As ruler of what was generally accepted as Byzantium in exile, Theodore I Lascaris of Nicaea faced initial difficulties which to lesser men would have been insurmountable. Quite apart from his rivals in Epirus and Trebizond - where in the autumn of 1204 David Comnenus was already advancing westward with alarming speed - petty Greek principalities were springing up like mushrooms within his own borders: one in Philadelphia, another in the valley of the Meander, yet a third in the obscure little town of Sampson near Miletus. Then, as the terrible year drew to its close, a Frankish army led by Baldwin himself, with his brother Henry and Count Louis of Blois, crossed the straits and began to move across Asia Minor. Theodore - who had been obliged to build up a whole new administrative machine as well as an army - was still hopelessly unprepared; and on 6 December 1204 he suffered a calamitous defeat at Poimanenon, some forty miles south of the Marmara - probably the modern Eski Manyas - giving the Franks control of the whole coastal region of Bithynia as far as Brusa (Bursa). Had they been able to continue their advance another sixty miles to Nicaea itself, Theodore's
Empire might well have been annihilated almost at its birth; fortunately for him, however, they were recalled in the nick of time by a serious crisis in the Balkans.
For Baldwin's arrogance had caught up with him. The Greek landowners in Thrace, who had initially been prepared to accept their Frankish overlords, now found themselves treated as second-class citizens. They rebelled, summoning to their aid the Bulgarian Tsar Kalojan and offering him the imperial crown if he could drive the Latins from Constantinople. The Tsar asked nothing better. Earlier in 1204 he had already been crowned King (though not Emperor) by Innocent Ill's envoy and had accepted the jurisdiction of Rome; this, however, in no way diminished his alarm at the proliferation of Latin states throughout the peninsula, and he was as anxious as were the Byzantines themselves to rid the land of the Crusader blight. By the beginning of 1205 he was on the march; and on 14 April he virtually annihilated the Frankish army outside Adrianople, killing Louis of Blois and taking prisoner the Emperor himself, who never regained his freedom and died soon afterwards. Thus, just a year after the capture of Constantinople, the power of the Latins was broken. In all Asia Minor, only the little town of Pegae (now Karabiga) on the southern shore of the Marmara remained in Frankish hands.
Now at last Theodore Lascaris could settle down in earnest to the forging of his new state - following, however, the old Byzantine pattern in every detail, for he never for a moment doubted that his countrymen would be back, sooner or later, in their rightful capital. Such members of the imperial household, officers of state and civil servants as he was able to track down were restored to their former posts; exiled bishops and other distinguished ecclesiastics were summoned to Nicaea, and -after the death of the Patriarch, who had stubbornly refused to leave his own place of refuge in Didymotichum - it was they who were invited to elect his successor. Their choice fell on a certain Michael Autorianus who, some time during Holy Week in 1208, crowned and anointed Theodore asbasileus.
There were now effectively two Eastern Emperors and two Patriarchs, the Latin in Constantinople and the Greek in Nicaea. Clearly there could never be peace between them: each was determined to destroy the other. Baldwin's brother and successor Henry of Hainault was for the first eighteen months of his reign fully occupied with Kalojan, who by the summer of 1206 had sacked Adrianople, mopped up most of Thrace and advanced to the very walls of the capital; but on 26 October 1207, while preparing to besiege Thessalonica, the Bulgar Tsar was murdered by a Cuman chieftain1 and Henry was able to increase the pressure on his rival in Nicaea. He did not march at once - he too, like Theodore, had had to set up a proper government and administration - but in 1209, conquering with some difficulty his Crusader scruples, he concluded a military alliance with Kaikosru, the Seljuk Sultan of Iconium, who also saw the establishment of a new Greek state in western Asia Minor as a provocation and a threat.
The Sultan, his forces now supplemented by a contingent of Frankish troops, was already preparing an expedition against Nicaea when he received an unexpected visitor: the former Emperor Alexius III. Towards the end of 1204 Alexius had fallen into the hands of Boniface, in whose castle of Montferrat he had spent several years as a prisoner. In 1209 or 1210, however, he had been ransomed by his cousin Michael, Despot of Epirus, and had made his way to Iconium in the vague hope that the Sultan might help him recover his throne. Now Kaikosru, it need hardly be said, was not interested in replacing the Greek Emperor so much as in eliminating him altogether; on the other hand he immediately recognized Alexius as a useful pawn in the diplomatic game, enabling him to set himself up as champion of a legitimate ruler against a parvenu usurper. With the ostensible aim of overthrowing Theodore and installing Alexius in his place, in the spring of 1211 he invaded Nicaean territory. The two sides - each of which had a contingent of Latin mercenaries at its core - were evenly matched, and there were several hard-fought though indecisive battles; but during the last, near Antioch on the Meander, the Sultan was unhorsed and killed - if Greek sources are to be believed, by the Emperor Theodore himself in single combat. The Seljuk army took to its heels; Alexius III was taken prisoner once again and dispatched to a monastery, where he was to spend the rest of his life.
The victory brought Theodore little territorial gain; but it eliminated his last Greek rival and - since Kaikosru's successor Kaikawus immediately came to terms - freed him at least temporarily from the Seljuk threat, enabling him to concentrate his forces exclusively against the
1 In his last campaigns Kalojan had killed as many Greeks as he had Latins, to the point where he proudly styled himself Romaioctonos ('killer of the Romaioi', i.e., the Byzantines) on the analogy of Basil II Bulgaroctonos. Not surprisingly he was by now detested by the Greeks, who saw the date of his death - the feast-day of St Demetrius of Thessalonica - as a clear indication that he had really been killed by the saint himself. The fact remains that it was Kalojan alone who had saved the Nicaean Empire from destruction by Baldwin three years before, and who had thus made it possible for the Greeks to regain Constantinople half a century later.
Crusaders. Here, alas, he was less successful. On 15 October 1211 beside the Rhyndacus river his army suffered another defeat by Henry, who advanced to Pergamum and Nymphaeum; but the Latins, by now once again hard pressed by the Bulgars in their rear, proved unable to pursue their advantage. In late 1214 the rival Emperors concluded a treaty of peace at Nymphaeum: Henry would keep the north-west coast of Asia Minor as far south as Atramyttion (now Edremit); all the rest as far as the Seljuk frontier, including the territories recently conquered by the Latins, would go to Theodore.
This treaty marked the beginning of Nicaean prosperity. The young Empire had finally obtained formal recognition by the Crusaders of its right to exist; moreover, its western borders were now as secure as those on the east. Almost simultaneously, the Ladn Empire began to decline. The widowed Emperor Henry, forced against his better judgement into a dynastic marriage with a Bulgar princess, found himself enmeshed in a hopeless tangle of Balkan politics; then, on 11 June 1216 at the age of only forty, he died suddenly at Thessalonica. By far the most capable of the Latin rulers of Constantinople, in barely a decade he had transformed a lost cause into a going concern. Unlike his insufferable brother Baldwin, he had respected the rights and the religion of his Greek subjects and had even achieved a balance of power with Nicaea. Had his successors possessed a fraction of his ability, there might never again have been a Greek Emperor on the throne of Byzantium.
Despite his two wives, Henry of Hainault had died childless; and to succeed him the Frankish barons in Constantinople elected his brother-in-law Peter of Courtenay, husband of his sister Yolanda. Peter, who was then in France, set out for the East in the first weeks of 1217. He had hoped to stop in Rome for a full-scale imperial coronation by Pope Honorius III; and he made no secret of his disappointment when the Pope, fearful that if the ceremony took place in St Peter's he might claim the crown of the Western Empire as well, insisted on holding it in the church of S. Lorenzo, outside the walls. A week or two later he set sail for Durazzo, accompanied by a Venetian fleet and an army of 5,500 men, with the object of recovering the city from the Despot of Epirus, Theodore Ducas; but the expedition ended in fiasco when the city proved impregnable and Peter was captured, together with a good many of his men, in the mountains of Albania. He was thrown into an Epirot prison and never heard of again.
The Empress Yolanda on the other hand, who had wisely decided to travel out with her children by sea, arrived without mishap in Constantinople, where she was almost immediately delivered of a son, Baldwin. Her first-born, the Marquis Philip of Namur, having categorically refused to accompany the rest of his family to the East, she then governed as Regent until her death in 1219, confirming her brother's conciliatory policy towards Nicaea by giving her daughter Mary to Theodore Lascaris as his third wife. News of this step, however, was received with horror in Epirus, where Theodore Ducas, not content with the capture - and quite possibly the murder - of Peter of Courtenay, was becoming less and less inclined to accept Lascaris as the lawful basileus.
Ducas's star was rising fast. Morally he was in a somewhat equivocal position, having spent the first five years after the fall of Constantinople in Nicaean territory with Theodore Lascaris to whom, after his imperial coronation, he had sworn an oath of fealty; he had eventually joined his brother Michael at Arta only on Michael's urgent summons. Since then, however, the situation had changed. Nicaea's treaty of 1214 with the Franks had been, to Theodore, an unpardonable betrayal; and the subsequent behaviour of its Emperor, who seemed to have spent much of his time fighting the distant Empire of Trebizond instead of preparing for the recapture of the capital, had strained his loyalty to near breaking point. Lascaris's marriage to a Latin princess was the last straw.
Such, at least, was his public position. The truth was a good deal simpler. Theodore could never be satisfied with the Despotate of Epirus. Unlike his bastard brother, he was the legitimate son of the sebastocrator John Angelus Ducas and thus the great-grandson of Alexius I Comnenus. With Comnenus, Angelus and Ducas blood in his veins - a fact which he emphasized by regularly styling himself with all three names - he could consequently boast a far stronger claim to the imperial throne than Theodore Lascaris.1 His immediate ambitions were now focused on Thessalonica; but Thessalonica was, after all, only the second city in the Empire: in the eyes of Theodore Angelus Ducas Comnenus, it was little more than a stepping-stone to his ultimate goal, Constantinople itself.
Things had not gone well for Thessalonica since Boniface of Montfer-rat had established himself there after the Fourth Crusade. Boniface had been killed fighting the Bulgars in 1207, and the Kingdom
1 The genealogy becomes a little complicated here, largely because of the understandable reluctance of the sebastocrator John (father of Michael and Theodore) to assume his father's name of Angelus, preferring to adopt that of Ducas, to which his only claim was through his grandmother; but a glance at the Comnenus and Angelus family trees should make the position clear.
had since been governed by his widow, acting as Regent for her son Demetrius. It had been further weakened by the departure of many of his knights to their various homelands and - though it was still the Latin Empire's most important vassal - since the arrival of the Empress Yolanda it could no longer rely on the firm support from Constantinople that it had enjoyed in Henry's day. When Theodore marched into Thessaly and Macedonia in 1218 it was plain that its days as an independent Crusader state were numbered. In fact, the Despot met with spirited resistance; and it was only in the autumn of 1224, after a long and arduous siege, that Thessalonica finally fell. With it fell its Latin Kingdom. Theodore now ruled supreme from the Adriatic to the Aegean, over a dominion which included Epirus, Aetolia, Acarnania, Thessaly and most of Macedonia. Soon afterwards - though the precise date is uncertain — in open defiance of Theodore Lascaris, he was crowned by the Bishop of Ochrid (who had a running feud with the Patriarch of Nicaea) as Emperor of the Romans.
Thus it was that, in place of the single Empire that had existed little more than a generation before, there were now three - two Greek and one Latin. And not far away there loomed yet a fourth: for the second Bulgarian Empire also was steadily increasing in strength. Tsar Kalojan had taken full advantage of the Fourth Crusade and the general Balkan disarray that followed it to extend his rule over much of Thrace and Macedonia. His nephew Boril had been rather less successful; but in 1218 Boril had been overthrown and blinded by his cousin John II Asen, and John too coveted Constantinople. Of the four powers, by far the weakest was the Latin Empire itself, by 1225 reduced to the region immediately to the north and west of the capital and a small area of Asia Minor south of the Marmara. The Empress Yolanda had died in 1219, leaving the throne to her son Robert; but Robert was a weak and feckless youth — one authority, a certain Aubrey de Trois-Fontaines, describes him as being quasi rudis et idiota — and was totally outclassed by Theodore, John Asen and John Vatatzes, who had inherited the Empire of Nicaea from his father-in-law Theodore Lascaris in 1222.
Lascaris had been a great ruler, who had achieved more than most people in 1205 would have thought possible. Since he left no sons, the choice of Vatatzes, husband of his eldest daughter Irene, had seemed an obvious one; it failed, however, to find favour with his two surviving brothers, who promptly made their way to Constantinople and persuaded the young Emperor to make a military intervention on their behalf. Robert, with characteristic stupidity, agreed; he achieved nothing, and his army was cut to pieces by Vatatzes at Poimanenon, where Theodore Lascaris had suffered a similar - though ultimately less disastrous -defeat at the hands of the Latins, twenty-odd years before. He had still not recovered from the blow when, a few months later, came the news of the capture of Thessalonica. It was too much for him. From that moment on he gave himself up to a life of pleasure, seducing women - Greek and Frankish indiscriminately - robbing churches and monasteries of their remaining treasures, making scarcely any attempt to govern what was left of his Empire. He also became infatuated with the daughter of a comparatively low-born French knight killed at the battle of Adrianople, whom he secretly married and installed in the Palace of Blachernae. This time it was his barons who could bear it no longer. One night several of them burst into the imperial bedchamber, where they slashed the girl's nose and lips until she was almost unrecognizable, seized her mother and subsequently drowned her. Typically, Robert took no action against them but at once fled to Rome, where he lodged a formal complaint with Pope Gregory IX. Gregory showed him little sympathy and told him to return to Constantinople; but he had got no further than Clarenza in the Morea - the modern Killini - when he died, in January 1228.
The Emperor Robert left no legitimate children; and since his brother and successor Baldwin II was still only eleven, once again a Regent had to be found. The first choice of the barons of Constantinople fell on his sister Mary, widow of Theodore Lascaris, who had returned to the city after the death of her husband; but she died a few months later, and the search was renewed. A somewhat surprising applicant was John Asen of Bulgaria, who suggested a dynastic marriage between Baldwin and his daughter Helena, after which he proposed to take the Empire under his own protection and restore to it all its conquered territories, Thessalonica included. But the barons rejected him out of hand, and turned instead to the most distinguished of living Crusaders: the former King of Jerusalem, leader of the Fifth Crusade1 and papal marshal John of Brienne.
There was only one drawback: John, having been born in about 1150, was now nearly eighty years old. But he was still remarkably spry - his daughter by his third wife, Berengaria of Castile, was still only four -and no one else could match his record. In 1210, at the age of sixty, he
1 Proclaimed by Innocent III at the Fourth Lateran Council of 1215, the Fifth Crusade was fought mostly in Egypt and has little direct relevance to our story.
had married the seventeen-year-old Queen Maria of Jerusalem. She had died in childbirth two years later, and John had ruled as effective King on behalf of his infant daughter Isabella until her marriage in 1225 to the Western Emperor Frederick II, Stupor Mundi - immediately after which he had been deposed by his new son-in-law on the grounds that, with his daughter now married, he no longer had any legal claim to the throne. Furious, he had fled to Rome, where he had appealed to Pope Honorius. Honorius had been sympathetic; he could not give him back his Kingdom, but he had appointed him Governor of his Tuscan patrimony. When two years later Gregory IX had succeeded to the papal throne and had been almost immediately attacked by imperial troops, John had rallied instandy to his defence.
Then, suddenly and unexpectedly, came the call to Constantinople. John was not at first over-eager to accept, but when Gregory insisted -here was, after all, an unrepeatable opportunity to increase papal influence over the Latin Empire - he finally allowed himself to be persuaded. He made, however, a number of conditions to protect his own future after Baldwin had reached his majority. The young Emperor must immediately marry Maria, his four-year-old daughter, who must in turn be given a suitable dowry in the form of land; he himself must be recognized as basileus in his own right for the rest of his life, with Baldwin succeeding him on his death; and at the age of twenty Baldwin, if not yet Emperor, should be invested with the Empire of Nicaea, together with all Frankish possessions in Asia Minor. Even then, John did not leave at once for Constantinople. It was early in 1229 before the barons gave their approval to his terms; and there was still a campaign to be fought against his hated son-in-law before he could leave Italy. Only in the autumn of 12 31 did he finally appear off the Golden Horn. A few days later he was crowned Emperor in St Sophia.
During this three-year interregnum, the balance of power in the Balkans had suffered a radical change. To the Emperor Theodore, waiting in his capital at Thessalonica, Constantinople - now without even a Regent to provide leadership - appeared more vulnerable than ever it had been; on the other hand, he had the Bulgars to consider. Only a year or two before, he and John Asen had concluded a treaty of peace; scarcely had they done so, however, than the Tsar had offered to recover Thessalonica for the Latins. The man could clearly not be trusted. Besides, with so dangerous a threat to the north, how could he possibly regain his ancient heritage? There was but one solution: the Bulgar menace must be eliminated. In the early spring of 1230, Theodore led his army across the frontier. Asen made a great show of outraged innocence, marching out against the invaders with the text of the peace treaty emblazoned across his standard; and in April 1230, near the little village of Klokotnitsa on the Maritsa river between Adrianople and Philippopolis, the two armies joined in battle.
It was all over quite quickly. Despite his courage, his confidence and his unbroken record of victories, Theodore found that he had met his match at last. His army was shattered, he himself taken prisoner. To be sure, his brother Manuel was allowed to stay on in Thessalonica with the title of Despot; but this was only because he was married to Asen's daughter. Manuel continued - much to the amusement of John Vatatzes and his Nicaean subjects - to sign decrees in the crimson ink reserved for Emperors; apart from that, he was an obvious puppet of his father-in-law and made little pretence of being anything else.
The Latins had been saved from almost certain destruction - and by a nation that they had previously spurned. Any gratitude that they might have felt must however have been overshadowed by alarm, as they watched John Asen advance unopposed across Thrace, Macedonia and Albania, effortlessly appropriating Theodore's former domains until he could claim as Bulgar territory the whole of the northern Balkans, from the Adriatic to the Black Sea. In an inscription in the church of the Forty Martyrs at his capital of Trnovo he proudly recorded his conquests. He was now, he claimed, master of all the lands between Durazzo and Adrianople; only Constantinople with its immediately adjacent towns remained in Frankish hands — 'and these too are subject to my authority, for they have no Emperor but myself and they obey my will, for God has so ordained it'. Even in theoretically independent Serbia he was able to replace Stephen Radoslav, who was Theodore's son-in-law, with Stephen Vladislav, who was one of his own. Nor was the Bulgar Tsar the only beneficiary of Klokotnitsa. Away in his palace at Nymphaeum, John Vatatzes was also quietly rejoicing. For a moment it had seemed as if Theodore might become a serious rival, and that Constantinople might fall to Thessalonica rather than to Nicaea; that danger was now past, never to return.
The effective elimination of the fourth participant in the struggle for supremacy led inevitably to a radical realignment among the other three. No longer would John Asen make diplomatic overtures to the Latins on the Bosphorus; it now seemed to him that Vatatzes would be a far more useful ally, particularly since he was on the point of another decision, even more far-reaching: to abandon the Church of Rome.
Western Christianity, despite Kalojan's conversion, had never taken root among the Bulgars, among whom the old Byzantine traditions had always prevailed; besides, any future offensive against the Latin Empire would be a lot easier to justify if the Tsar were not seen to be attacking his co-religionists. A quarrel with Pope Gregory in 1232 gave him just the excuse he needed, and the break was made. With the ready consent of the Patriarch of Nicaea - together with those of Jerusalem, Alexandria and Antioch - a Bulgarian Orthodox Patriarchate was once again established, with its seat at Trnovo; and three years later in Gallipoli John Asen signed a treaty of alliance with Nicaea, which was subsequently sealed in Lampsacus by the marriage of his daughter Helena -rejected by young Baldwin seven years before - to the son of John Vatatzes, Theodore II Lascaris. In the late summer of 1235 the combined forces of Orthodoxy were outside the walls of Constantinople, besieging the city by land and sea.
Once again the Latins were under threat. Despite his age, John of Brienne fought like a tiger for the defence of his Empire, and Venetian ships provided invaluable support; when, however, the siege was resumed in the following year Constantinople would surely have been doomed but for a sudden change of heart on the part of John Asen, who awoke one morning to the realization that an energetic Greek Empire would constitute an infinitely more serious threat to Bulgaria than an exhausted Latin one and called off the attack, even going so far as to send ambassadors to Nicaea to retrieve the unfortunate Helena. In the summer of 1237 he went further still, allowing a large band of Cumans, fleeing from the Mongol invasion of the lower Danube basin, to cross his territory and take service with the new Emperor Baldwin - John of Brienne having died, aged nearly ninety, the previous March; and that autumn he himself led an army of Bulgars, Cumans and Latins against Tzurulum, one of the most important Nicaean strongholds in Thrace.
That siege was still in progress when disaster struck. Messengers arrived with the news that Trnovo was in the grip of a furious epidemic, which had already carried off the Tsar's wife, one of his sons and the recently-installed Patriarch. To John Asen, this could only be the judgement of heaven. He immediately withdrew from the siege (which was successfully continued by his Cuman and Latin allies) and made peace with Vatatzes, to whom he was to give no further trouble. Soon, however, he began to look for a new wife; and somehow his prisoner Theodore of Thessalonica - whom he had recently had blinded for plotting against him - managed to persuade him to marry his daughter
Irene. The diplomatic advantages to John Asen of such a marriage are not altogether clear; to Theodore, on the other hand, they were immediate. As the Tsar's father-in-law, he was at once released from his captivity and returned in disguise to Thessalonica, where he deposed his brother Manuel and enthroned instead his own son John, restoring to him the title of Emperor.
The year 1241 proved a watershed in the history of all the contesting Empires. Before it was over, three of the protagonists in the long drawn-out struggle for Constantinople were in their graves: John Asen of Bulgaria, Manuel of Thessalonica and Pope Gregory IX, one of the most redoubtable and consistent champions of the Latin Empire. More important still, that same year also saw the Mongol horde under its leader Batu Khan sweep through Moravia and Hungary into the Danube basin, leaving the Bulgars little opportunity to involve themselves in further adventures to the East. Thus another once formidable nation was effectively eliminated. The power of Thessalonica had already been broken at Klokotnitsa. The Latin Empire, which had been steadily cut down to the point where it amounted to little more than the city of Constantinople itself, had survived only thanks to dissension among its enemies. Of those enemies, there now remained but one: the Empire of Nicaea, whose ruler John Vatatzes continued to prepare, with steadily increasing confidence, for the reconquest of the ancient capital.
He still had the problem of Thessalonica to settle. Although the so-called Empire was no longer a threat from the military point of view, legally it remained a rival claimant to Constantinople - a position that clearly could not be tolerated. Its Emperor John he knew to be a weak and pious figurehead, who longed only to enter a monastery; the real power, such as it was, was back in the hands of Theodore, as ambitious - despite his blindness - as he had ever been. Thus it was Theodore whom, towards the end of 1241, John Vatatzes invited to Nicaea as his guest. The invitation was accepted, and the old man was received with every courtesy; only when he came to take his leave was it politely explained to him that his departure would unfortunately not be possible. He was in fact a prisoner, and a prisoner he remained until the following summer, when Vatatzes escorted him back to Thessalonica with a considerable army and then sent him as an envoy to his son to negotiate a treaty. The result was that John, like Manuel before him, agreed to exchange the title of Emperor for that of Despot, and acknowledged the supremacy of Nicaea.
While Vatatzes was still in Thessalonica, word was brought to him that the Mongols had invaded the Seljuk lands of Asia Minor and were already on the very threshold of his own dominions. For the next few years the situation looked grave indeed, especially after June 1243, when the invaders defeated the Sultan Kaikosru II at the battle of Kosedag and forced him to pay tribute. The Emperor of Trebizond, who had been a vassal of the Sultan, suffered much the same fate and was obliged to transfer his allegiance to the Mongol Khan. In face of the common danger, Vatatzes concluded an alliance with Kaikosru, but the precaution proved unnecessary: the Mongols moved away again, leaving the Nicaean lands untouched and his own position vis-a-vis his neighbours stronger than ever.
In 1244 he was able to strengthen it still further. His first wife Irene, daughter of his predecessor Theodore Lascaris, had died; and John now married Constance, the illegitimate daughter of Frederick II. Frederick had no quarrel with the Emperor Baldwin, to whom he was distantly related; but having been brought up in the largely Greek court of Palermo he knew and understood the Greeks, spoke their language perfectly and sympathized with them in their long exile from their rightful capital. He was therefore delighted with the match - though the same could not be said for the twelve-year-old Constance, who found herself rechristened with the more Byzantine name of Anna and wedded to a man exactly forty years older than herself, a man moreover whom everyone knew to be engaged in a shameless affair with one of her own waiting-women. Pope Innocent IV was deeply shocked by the marriage, just as the Patriarch of Nicaea was horrified by Vatatzes's treatment of his luckless young wife; but the friendship between the two Emperors remained unaffected.
With the Mongols gone - leaving a broken Sultanate behind them -John Vatatzes could now turn his attention back again to the Balkans. The Bulgar Empire too had been crippled by this most recent of the barbarian invasions; while the death in 1246 of Tsar Coloman, John Asen's twelve-year-old son, and the succession of his still younger half-brother Michael, further troubled the waters in which Vatatzes cheerfully intended to fish. By the autumn of that year he had taken Serres, and from there had occupied all the territory between the Strymon and Maritsa rivers together with a good deal of western Macedonia. He was still encamped at Melnik on the Strymon when a group of Thessalonians arrived with a proposal. When the Despot John had died two years before, his father Theodore had replaced him with his younger brother
Demetrius; but Demetrius had proved dissolute and pleasure-loving, and a large number of his subjects had now had enough, of him and his entire family. If the Emperor would guarantee to the city the continuation of its ancient rights and privileges, it would be surrendered to him without a struggle. Vatatzes asked nothing better. In December he entered Thessalonica unopposed, exiled old Theodore to a country estate and took Demetrius back to Asia Minor as his prisoner, leaving as his European Viceroy his distant kinsman Andronicus Palaeologus.
One more enemy was left to conquer before he could concentrate on Constantinople. Some nine years before, the region of Epirus had separated from Thessalonica and set itself up once again as an independent despotate under Michael II, an illegitimate son of its original founder Michael I. It too had taken advantage of the Mongol occupation of Bulgaria, and had regained much of the territory conquered by John Asen in 1230; around Ochrid and Prilep, it now shared a common frontier with the Empire of Nicaea. John Vatatzes did not attack it: in such wild and mountainous terrain a war might go on for years. Instead, in 1249 he concluded a treaty of friendship with Michael, sealing it by betrothing his granddaughter Maria to Michael's son Nicephorus.
All would have been well if the aged Theodore, still making as much trouble as ever, had not persuaded his nephew to renounce the treaty and take up arms once again against the Nicaean Empire. In 1251 Michael obediently did so, capturing Prilep and advancing as far as the Axius river (now the Vardar). John Vatatzes was taking no more chances. He crossed to Europe with the largest army he could raise, and early in 1253 forced the Despot's surrender. Michael had good reason to regret his foolishness: he was obliged to cede not only the territory he had recently occupied but also all that region of western Macedonia that he had conquered from the Bulgars and part of Albania as well. His son Nicephorus was carried off to the court of his grandfather-in-law-to-be as a hostage for his future good behaviour. As for the old, blind, insufferable Theodore, he too was shipped across the Marmara, to end his days in the prison he so richly deserved.