Sis (mod. Kozan, Turkey) was a fortress and town that was the capital of the Armenian kingdom of Cilicia (1198-1375). It lay at the foot of the Taurus Mountains on a tributary of the Pyramus (mod. Ceyhan Nehri).
The earliest mentions of Sis are as a frontier fortress during the wars between the Byzantines and the ‘Abbāsid caliphs; it was captured by the Byzantines in 962. Mentions of Sis in the early crusade period are scarce; it was apparently taken by the Rupenid prince T‘oros I in 1113-1114. Situated some 50 kilometers (c. 31 mi.) south of the original Rupenid base at Vahga in the mountains, it gave better access to the plain, and it seems to have been the prince’s chief residence from the time of Mleh (1169-1175). While at this time it lacked a bishop, there was an archbishop by 1197, and after the fall of Hromgla (1292) Sis became the seat of the catholi- cos of the Armenian Orthodox Church. The coronation of King Leon I of Armenia took place at Tarsos (mod. Tarsus, Turkey), but later ceremonies were held at Sis (Leon invested his intended heir there in 1211), and it became the regular seat of the royal court.
The ruined fortress, high on an isolated mountaintop above the town, is still impressive, but the town itself was never walled. The royal palace and ecclesiastical complex on the slopes of the citadel had some protection but were exposed to serious attacks. From the later thirteenth century Mamlûk raids repeatedly sacked the town; in 1266 the army of Sultan Baybars I burned the cathedral and sacked the royal treasury; in 1302 King Het‘um II was nearly captured from among fugitives making for the citadel; in 1337 the citadel was itself sacked. Sis remained the capital of the weakened kingdom until its final capture by the Mamlūks in 1375.