Armenia. On his return voyage, he remained much longer, receiving visits from local princes, bishops, and abbots. Het'um and his forces fought under the Mongol banner of Hulagu in the conquest of Muslim Syria and the capture of Aleppo and Damascus from 1259 to 1260. The involvement of Het'um at these two conquests is debated however, with the source for such information - Templar of Tyre - claiming his involvement in a deliberate attempt to integrate Mongols into a Holy-War conquest narrative. This was to persuade Latin Christendom of the need for a war against the Mamluks. According to Arab historians, during Hulagu's conquest of Aleppo, Het'um and his forces were responsible for a massacre and arsons in the main mosque and in the neighboring quarters and souks. Meanwhile, the Egyptian Mamluks had been replacing their former Ayyubid masters in Egypt. The Mamluks began as a cavalry corps established from Turkic and other slaves sold to the Egyptian sultan by Genghis Khan. They took control of Egypt and Palestine in 1250 and 1253, respectively, and filled the vacuum caused by the Mongol destruction of the pre-existing Ayyubid and Abbasid governments. Cilician Armenia also expanded and recovered lands crossed by important trade routes on the Cappadocian, Mesopotamian, and Syrian borders, including Marash and Behesni, which further made the Armenian Kingdom a potential Mamluk target. Armenia also engaged in an economic battle with the Mamluks for control of the spice trade. The Mamluk leader Baibars took the field in 1266 with the intention of wiping out the Crusader states from the Middle East. In the same year, he summoned Het'um I to change his allegiance from the Mongols to the Mamluks, and remit to the Mamluks the territories and fortresses the Armenian king had acquired through his submission to the Mongols. After these threats, Het'um went to the Mongol court of the Il-Khan in Persia to obtain military support, but in his absence, the Mamluks invaded Cilician Armenia. Het'um's sons T'oros and Levon were left to defend the country. During the Disaster of Mari, the Mamluks under Sultan Al-Mansur Ali and the commander Qalawun overran the heavily outnumbered Armenians, killing T'oros and capturing Levon. Afterwards the capital of Sis was sacked and burnt, thousands of Armenians were massacred and 40,000 taken captive. Het'um ransomed Levon for a high price, giving the Mamluks control of many fortresses and a large sum of money.