He succeeded on his father's death in 1270, when he was 11 years old. He ruled for some time under the regency of
Sadun Mankaberdeli, the
Atabeg and
Amirspasalar designated by the Mongols. It is for this reason that upon the death of Sadun in 1282, Demetrius refused the post of atabeg to his son
Khutlubuga and made him a sworn enemy. Although he continued to be titled "king of Georgians and Abkhazians, etc", Demetrius's rule extended only over the eastern part of the kingdom.
Western Georgia was in the hands of the descendants of
David VI Narin who proclaimed themselves kings of western Georgia, while the province of
Samtskhe, governed by the independent prince
Beka I Jaqeli, was directly subject to the Mongols. Demetrius also participated in the
Mongol campaigns in the
Middle East against the
Mamluks of
Egypt and particularly distinguished himself with Beka I Jaqeli at the head of a Georgian army of 15,000 men under the orders of
Möngke Temür, brother of
Abaqa Khan, during the
Second Battle of Homs in 1281. Despite the defeat of the Mongol troops, the
Georgians reported significant spoils. during the rule of Demetrius II, with Chritian cross.
Tiflis mint, 1281–1286. Demetrius behaved like a loyal subject of the
Ilkhan; he was a supporter of
Tekuder (1282-1284), a Mongol converted to
Islam, then of
Arghun (1284-1291), brought to the throne in reaction by traditional Mongol
Buddhist or
Nestorian leaders. He developed friendly relations with the Mongolian nobility. Although he was already married to a
Greek princess of
Trebizond, he took the Mongolian princess Solghar as his second wife. In 1288, on the order of Arghun, he subdued the rebel province of
Derbent, near the
Caspian Sea. The same year, Arghun revealed a plot organized by his powerful minister
Buqa, whose son was married to Demetrius's daughter. Bugha and his family were massacred, and the Georgian king, suspected to have been involved in the plot, was ordered to ride to the Mongol capital, lest Arghun threatened to invade Georgia. Despite much advice from nobles, Demetrius headed for the Khan's residence to face apparent death, and was imprisoned there. He was beheaded at Movakan on 12 March 1289. He was buried at
Mtskheta,
Georgia, and canonized by the
Georgian Orthodox Church. He was succeeded by his cousin
Vakhtang II. ==Marriages and children==