David IV, also known as David IV the Builder (დავით IV აღმაშენებელი, Davit IV Aghmashenebeli) (1073–1125), of the Bagrationi dynasty, was the 5th king of United Georgia from 1089 until his death in 1125. Popularly considered to be the greatest and most successful Georgian ruler in history and an original architect of the Georgian Golden Age, he succeeded in driving the Seljuk Turks out of the country, winning the Battle of Didgori in 1121. His reforms of the army and administration enabled him to reunite the country and bring most of the lands of the Caucasus under Georgia's control. A friend of the Church and a notable promoter of Christian culture, he was canonized by the Georgian Orthodox Church. The epithet aghmashenebeli (აღმაშენებელი), which is translated as "the Builder" (in the sense of "built completely"), "the Rebuilder", or "the Restorer", first appears as the sobriquet of David in the charter issued in the name of "King of Kings Bagrat" in 1452 and becomes firmly affixed to him in the works of the 17th- and 18th-century historians such as Parsadan Gorgijanidze, Beri Egnatashvili and Prince Vakhushti. Epigraphic data also provide evidence for the early use of David's other epithet, "the Great" (დიდი, didi). Retrospectively, David the Builder has been variously referred to as David II, III, and IV, reflecting substantial variation in the ordinals assigned to the Georgian Bagratids, especially in the early period of their history, owing to the fact that the numbering of successive rulers moves between the many branches of the family. Scholars in Georgia favor David IV, his namesake predecessors being: David I Curopalates (died 881), David II Magistros (died 937), and David III Curopalates (died 1001), all members of the principal line of the Bagratid dynasty. Family of David IV of Georgia The year of David's birth can be calculated from the date of his accession to the throne recorded in the Life of King of Kings David (ცხორებაჲ მეფეთ-მეფისა დავითისი), written 1123–1126, as k'oronikon (Paschal cycle) 309, that is, 1089, when he was 16 years old.