‘Izz al-Dīn Qilij Arslān II (Turk. lzzüddin Kiliç Arslan II) was the sixth Saljûq sultan of Rûm (1156-1192), in whose reign the sultanate, centered on Ikonion (mod. Konya, Turkey), assumed a leading role in Anatolian affairs by defeating the Byzantines, annexing the two Dānishmendid emirates, and contracting an alliance with the Holy Roman Emperor and crusading leader Frederick I Barbarossa.
Qilij Arslān II was born around 1115, the son of Sultan Mas‘ûd I (d. 1156). Although his brother’s claim to the succession was supported by Nûr al-Dīn, the ruler of Muslim Syria, Qilij Arslān II finally prevailed. Among his first tasks was to thwart a possible alliance between Nûr al-Dīn and Emperor Manuel I Komnenos of Byzantium, with whom he had signed an ineffectual treaty in 1158; for this reason he visited Constantinople in 1161-1162, where he was magnificently received for three months by Manuel and a new treaty was signed. However, this treaty was not observed, since in 1173/1174 the sultan signed another treaty with Byzantium’s bitter Western enemy, Frederick I Barbarossa. Thus Manuel I decided to invade Anatolia, where he fortified the fortresses of Dorylaion and Choma-Soublaion (1175/1176), but, rejecting Qilij Arslān II’s peace offer, he was eventually heavily defeated in September 1176 at Myriokephalon, in west-central Anatolia.
This victory enabled the sultan to expand his conquests at the expense of Byzantium until the mid-1180s. Meanwhile, between 1174 and 1177/1178, he succeeded in annexing the strongholds of the two Dānishmendid dynasties of Sebasteia (mod. Sivas, Turkey) and Melitene (mod. Malatya, Turkey). In the last years of his reign, when the Byzantines contracted alliances with Saladin (1184-1185 and 11891192) and the Rupenids of Cilicia solidified their grip on the Taurus-Antitaurus area, Qilij Arslān II faced difficulties with his nine ambitious sons, each of whom possessed an important Anatolian city as emir and aspired to the throne. Around 1189/1190 the eldest son, Qutb al-Dīn, prevailed over his old and sick father at Ikonion, but with the advent of Frederick I at the head of the German army of the Third Crusade in Anatolia (1190), the Sāljuq capital was taken and, following Qutb al-Dīn’s death (c. 1191), it was restored to Qilij Arslān, who lived there until he died (August 1192) under the protection of his youngest and favorite son, Kay-Khusraw I, who succeeded him.