On April 15, 1277, the Mamluk Sultan Baibars marched from Syria into the Mongol-dominated Seljuk Sultanate of Rûm and attacked the Mongol occupation force in the Battle of Elbistan (Abulustayn). Upon reaching Elbistan with at least 10,000 horseman, Baibars made ready for battle with the Mongols, expecting them to be around 30,000. However, although the Mongol forces were smaller than the Mamluk army, there were the Georgians and Rum Seljuks that bolstered their numbers.
After Baibars victory, he marched unopposed to Kayseri in the heart of Anatolia in triumph and entered it on April 23, 1277 just over a month after the battle. The Mongol Ilkhan Abaqa, meanwhile reasserted his authority in Rum. After Abaqa surveyed the battlefield he became very angry. He ordered the Muslim population of Kayseri and eastern Rum to be put to death. Large numbers of people were killed.