After the Mamluk victory over the Mongol Ilkhanate at Ain Jalut in 1260, where a force of reportedly 500 Armenian knights and their retinues also participated, the Mamluk armies started a series of devastating raids against the Kingdom of Cilician Armenia, an ally of the Ilkhanate and a prosperous Christian state bordering the Eastern Mediterranean. Notably, in 1266, in the absence of the Mongol allies and of King Hethum I who was traveling to Karakorum to summon help, the Armenians suffered a crushing defeat while taken by surprise by the Mamluk army at Mari, near Darbsak. In 1275, the Mamluk Sultan Baibars invaded Cilician Armenia, sacked its capital Sis (but not the citadel) and demolished the royal palace. His marauding troops massacred inhabitants of the mountain valleys and took large quantities of booty. The port city of Ayas was destroyed and burned by a Mamluk column and some 2000 Frankish and Armenian inhabitants drowned while attempting to take refuge on the ships in the harbor. The Cilician Plain was laid waste and its inhabitants put to the sword or carried as prisoners. According to eyewitnesses, only those who took refuge in fortified places escaped the carnage. The city of Tarsus was also ruined. In this context, Armenian nobility, mostly safe in its mountain strongholds, rallied around King Leo II (the son of Hethum I) and Constable Sempad.