During the Baltic Crusades the peoples populating Finland became both targets and participants in the crusades. When the crusades began, the names “Finns” and “Finland” (Finn. Suomi) referred only to the inhabitants of the southwestern parts of present-day Finland around Turku (Sw. Åbo), so-called Finland Proper. The extension of the nameto other Finnic neighbors to the east, the Tavastians (Finn. Hame) and the Karelians (Finn. Karjalaiset), was a direct consequence of the crusades. All three Finnic tribes lived in the vicinity of one of the ancient trade routes between east and west, and archaeological excavations suggest that by the middle of the eleventh century they had become acquainted with Christianity in both its Eastern and Western forms. However, their societies remained largely pagan, and the wholesale Christianization of the population and its incorporation into the Latin Church were the result of crusades that were launched from Sweden and, for a brief period, Denmark.
The importance of the crusades for Finland is reflected in the fact that the established term for the period 1150-1350 in modern Finnish historiography is the “Crusade Age.” This again reflects a tradition in Swedish historiography founded by the historian and poet Erik Gustaf Geijer (1783-1847). According to him, the Swedish conquest of Finland came about as a result of three successive crusades. The “First” Swedish Crusade is known only from the thirteenth-century life of the king and saint Erik IX Jedvardsson (d. 1160). This was a crusade to Finland Proper that is supposed to have taken place around 1155/1157, led by King Erik and one Henry, an Englishman alleged to have been bishop of Uppsala. Erik returned to Sweden, where he was killed soon after, while Henry stayed on in Finland, where he was martyred. Bishop Henry was considered to be the first bishop of the Finns and later became venerated as Finland’s patron saint.
The establishment of the Swedes in Finland during this period is confirmed in a bull from Pope Alexander III dating from 1171/1172. Rehearsing Swedish complaints that the Finns promised to observe the Christian faith whenever they were threatened by an enemy army, but, when the army retreated, denied the faith and persecuted the priests, the pope ordered the Swedes to force the Finns to observe the Christian creed. Although Bishop Henry’s role remains obscure, there is no doubt that this period saw the establishment of a missionary bishopric for the Finns and Finland, later permanently located at Turku and linked to the Swedish archbishopric in Uppsala.
In the early period the Swedes were not alone in organizing crusades to Finland. The Danes are recorded as having launched at least two expeditions there. Until the establishment of the archbishopric of Uppsala by Pope Alexander III (1164), the Danish archbishopric in Lund was the metropolitan of the Swedish bishoprics and therefore had a legit imate interest in the mission to Finland. Alexander also stipulated that the archbishop of Lund was to remain the primate of the Swedish church (Lat. Swetiae primas), and so for most of the century after 1164 much papal policy regarding the eastern Baltic region was channeled to the Swedish church through the Danish archbishop, who often had the status of papal legate for the region. This may explain why it was the Danish archbishop, rather than the Swedish one, who was authorized by Pope Innocent III to install a new bishop in Finland in 1209.
According to Danish annals, King Knud VI of Denmark sent an expedition to Finland in 1191 and “won it” [Danmarks middelalderlige annaler, ed. Erik Kroman (København: Selskabet for udgivelse af kilder til dansk historie, 1980), p. 18]. In 1202 another Danish army went to Finland under the leadership of Anders Sunesen, archbishop of Lund, and his brothers. They are also recorded as having led an expedition to Estonia in 1206. It is unclear whether these actions were undertaken in collaboration or competition with the Swedish crusades. The Sunesen brothers had close links with the Swedish king Sverker II Karlsson, who was married to their sister, and supported him against a rival claimant to the throne, Erik Knutsson. A more likely possibility is that the Danish activities in Finland were planned in conjunction with the Danish crusades to Estonia. In that case, it is probable that the Danes were not interested in the same areas as the Swedes, but rather, in the southern coastal regions along the Gulf of Finland. This is suggested by the evidence of the so-called Danish Itinerary, a thirteenth-century itinerary contained in a Danish manuscript (MSKøbenhavn, Rigsarkivet, C8), often known as Codex ex-Holmiensis A 41 or Kong Valdemars Jordebog. This work outlines a sailing route from the Danish territory of Blekinge (in mod. southern Sweden) across the Baltic Sea to Reval (mod. Tallinn, Estonia). A link with the crusades is indicated by the fact that it is transmitted together with a second itinerary from Ribe in Denmark to Acre (mod. ‘Akko, Israel) in Palestine. The Baltic itinerary follows the Swedish coast as far as the Stockholm Archipelago, then crosses to the southern coast of Finland, which it follows to the Porkkala Peninsula just west of present-day Helsinki. Here, where the distance is shortest, it turns south across the Gulf of Finland to Reval. The itinerary itself, its references to an island called Jutlanders’ Island, and both Danish and Finnish names for some localities all suggest that Danish interest in Finland was focused on the southern coast around the Pokkala Peninsula.
However, Danish authority in this part of Finland must have collapsed together with other parts of the Danish crusading empire after 1223, when King Valdemar II Sejr was kidnapped by his rebellious vassal Count Henry of Schwerin.
The sudden disappearance of Danish power may explain signs of a crisis of Christianity in Finland, which is revealed in two bulls of Pope Gregory IX. In 1232 Gregory appointed Baldwin of Aulneas his legate with authority to solve the current crises in both Livonia and Finland, and later that year, he found it necessary to ask the Order of the Sword Brethren in Livonia to help the Christians in Finland, who were allegedly threatened by the Russians. Soon after the Danish collapse, the Sword Brethren had taken control of Danish Estonia, and they may have been the Christian force best placed to intervene in Finland. However, it is unclear whether the Sword Brethren were able to intervene in Finland before their near-annihilation in 1236 at the battle of Saule. In December 1237, the pope issued a new bull at the instigation of the archbishop of Uppsala, who claimed that the Tavastians had apostatized and now threatened the Christian plantation in Finland. The pope ordered the archbishop and his suffragans to preach a crusade against the Tavastians.
The immediate result seems to have been the “Second” Swedish Crusade to Finland, led by Birger Magnusson, brother-in-law of the king. The actual campaign is only known from the rhymed Erik Chronicle, written in the 1320s. The chronicle gives no date for the crusade, but it presumably took place in 1238 or 1239: according to Novgorodian chronicles, in 1240 Birger Magnusson was able to lead his bishops in a further crusade to the river Neva against Novgorod, accompanied by both Finns and Tavastians. In Tavas- tia, a castle, presumably Hakoinen, was built as a center of Swedish power, later to be supplanted by a new fortress at Hameenlinna (Sw. Tavastehus). The Tavastians must soon have been firmly integrated into the Swedish realm and church. In summer 1256 they once more participated in Swedish operations against Novgorod, together with the Finns. This time the Swedes sent their fleet across the Gulf of Finland, where they started to build a fortress on the Nov- gorodian side of the river Narva together with one of the Danish vassals in Estonia.
Around this time, the Swedes began to colonize the thinly populated areas on the coasts of the Gulf of Bothnia and, more importantly, along the Gulf of Finland, where the Danish strongholds had presumably been situated. Control of this coastal region, which became known as Nyland (New Land), was a necessary precondition for the next stage in the Swedish crusades, which were now to be directed against Karelia, at this time under the rule of the Russian city-state of Novgorod. Plans for this so-called “Third” Swedish Crusade were being made by the mid-thirteenth century. King Valdemar Birgersson procured a crusading bull against the Karelians from Pope Alexander (1254-1261), who also issued a bull against the Russians. It took another thirty years before military operations in Karelia got under way. In 1293 the Swedes established a fortress at Viborg (mod. Vyborg, Russia), which blocked the entrance to the river Vuoksi. However, they failed to take and hold the Karelian center of Kexholm (Russ. Korel’skii Gorodok or Priozërsk) on the opposite shore of the Vuoksi at Lake Ladoga, and in 1301 they also lost the fortress of Landskrona, which they had started building the previous year. The war continued for another twenty years before Sweden and Novgorod concluded the Treaty of Noteborg (Pahkinasaari) in 1323, which fixed a border between Sweden and Russia for the first time.
Some subsequent crusades were launched against Russia by Sweden from Finnish territory, notably the crusade of King Magnus II Eriksson (1347-1351), but these had little importance for Finland. The further expansion of Finnish territory at the expense of Russia was the result of a gradual colonization in the north or later wars that had nothing to do with the crusades. Despite the evidence in papal letters of resistance by both Finns Proper and Tavastians, their respective incorporation into the Swedish realm and church progressed relatively smoothly. One reason may have been that there existed a tradition of collaboration between Swedes and Finns that predated the arrival of Christianity. Also, the Finns were not subjugated by a foreign aristocracy but instead incorporated into Swedish society on equal terms. Therefore, north of the Gulf of Finland, there is no evidence of a division of the population into a ruling upper class and a repressed lower class along ethnic lines, as was the case in Livonia south of the gulf. This state of affairs may also reflect the fact that from 1240 onward, Swedish rulers looked beyond Finland and wanted the Finnish tribes as allies in future drives toward the east. It is not surprising that after the Swedes had incorporated the Finnish provinces, the Finns and Tavastians are repeatedly named as their allies in Russian sources.