A decisive battle fought between the Georgians and a Muslim coalition at Basian (near Erzurum in mod. Turkey).
The reign of Queen Tamar of Georgia (1178-1213) underscored Georgian might after a large Muslim coalition was crushed in battle at Shamkhor in 1195. Alarmed by the Georgian success, Rukn al-DinSulaymân Shah II, sultan of Rûm (1196-1204), rallied the Muslim principalities of Asia Minor against Georgia. A massive Muslim army advanced toward the Georgian borders in 1203 and was met at Basian by a much smaller Georgian force under David Soslani, king consort to Tamar. The Georgians initially made an unexpected attack with their advance guard and spread confusion among the enemy troops. The sultan managed to rally his forces and counterattacked, but was surprised by coordinated flanking attacks, which routed his forces. The bitterly contested battle caused heavy casualties on both sides. The victory at Basian secured Georgian preeminence in the region. Exploiting her success in this battle, Queen Tamar annexed Arran and Duin in 1203, and subdued the emirate of Kars, the Armen-Shahs, and the emirs of Erzurum and Erzincan. In 1204, she provided military and political support to Alexios Komnenos in establishing the empire of Trebizond. The Georgians then invaded Azerbaijan, advancing as far as Ardabil and Tabriz in 1208 and Qazvin and Khoy in 1210. These victories brought Georgia to the summit of its power and glory, establishing a pan-Caucasian Georgian Empire stretching from the Black Sea to the Caspian and from the Caucasus Mountains to Lake Van.