great cathedrals, romantic poetry and literature, and the epic poem "The Knight in the Panther's Skin". David the Builder is popularly considered to be the greatest and most successful Georgian ruler in history. He succeeded in driving the Seljuks out of the country, winning the major Battle of Didgori in 1121. His reforms of the army and administration enabled him to reunite the country and bring most lands of the Caucasus under Georgia's control.
David the Builder's granddaughter Tamar succeeded in neutralizing opposition and embarked on an energetic foreign policy aided by the downfall of the rival powers of the Seljuks and Byzantium. Supported by a powerful military élite, Tamar was able to build on the successes of her predecessors to consolidate an empire which dominated the Caucasus, and extended over large parts of present-day Azerbaijan, Armenia, and eastern Turkey, until its collapse under the Mongol attacks within two decades after Tamar's death.
The revival of the Georgian Kingdom was set back after Tbilisi was captured and destroyed by the Khwarezmian leader Jalal ad-Din in 1226. The Mongols were expelled by George V of Georgia, son of Demetrius II of Georgia, who was named "Brilliant" for his role in restoring the country's previous strength and Christian culture. George V was the last great king of the unified Georgian state. After his death, different local rulers fought for their independence from central Georgian rule, until the total disintegration of the Kingdom in the 15th century. Georgia was further weakened by several disastrous invasions by Tamerlane. Invasions continued, giving the Kingdom no time for restoration, with both Black and White sheep Turkomans constantly raiding its southern provinces. As a result, Georgian Kingdom collapsed into anarchy by 1466 and fragmented into three independent Kingdoms and five semi-independent principalities. Neighboring empires exploited the internal division of the weakened country, and
