He was the son of King Leo II of Armenia and Queen Keran, and was part of the Hethumid dynasty, being the grandson of Hethum I, who had originally submitted Cilicia to the Mongols in 1247.

As part of this relationship, Cilician Armenia routinely supplied troops to the Mongols, cooperating in battles against the Mamluks and other elements of the Islamic empire.

At the time, Cilician Armenia was in a precarious position between major powers, balancing between friendly relations with the Christian European Crusaders and Byzantine Empire, aggression from the Turkish Karamanids to the west and the Turkish Sultanate of Rum to the north, a vassal relationship with the aggressive Mongol Empire in the east, and defending itself from attacks from the south, from the Muslim Mamluk Sultanate out of Egypt.

His father the Mamluk sultan Qalawun had earlier broken the treaty of 1285, was marching North through Palestine with his troops, and also demanded the surrender of the Armenian cities of Marash and Behesni.

Khalil's forces continued on from there, sacking the Armenian city of Hromgla, which was defended by Hethum's uncle, Raymond, but fell after a siege of 33 days.

He did stay active in the politics of the kingdom though, and negotiated with the Egyptian leader Ketbougha for the return of the prisoners who had been taken at Hromgla, as well as for some church relics which had been pillaged.

Hethum and Thoros placed Armenia under the regency of their brother Sempad, and traveled to Constantinople to bestow their sister Rita upon the Byzantine Emperor Michael IX Palaeologus.

[6][7] However, Claude Mutafian, in Le Royaume Arménien de Cilicie, suggests that it may have been on this occasion that Hethum remitted his amber scepter to the Armenian convent of Saint James of Jerusalem.

He then returned to join Ghazan in Damas, and spend the winter with himSpeculation aside, the Mongols retreated northwards a few months later, and the Mamluks reclaimed Palestine with little resistance.

The Armenians again joined forces with a sizable number of Mongol troops, 80,000, on a Syrian offensive, but they were defeated at Homs on 30 March 1303, and at the decisive Battle of Shaqhab (Merj-us-Safer), south of Damas, on 21 April 1303.

The Armenian Kingdom of Cilicia's alignment with the Mongol Empire continued, motivated as much by the need for self-protection from the Seljuk Sultanate of Rûm on their western borders as self-interest in acquiring territory to the east, albeit short-lived.

He was subsequently summoned by Bilarghu to a meeting on 17 November 1307, in an encampment beneath the walls of the royal stronghold of Anazarbus (Caesarea in the Roman province of Cilicia), either to hold counsel or for a banquet.