Recognizing the Byzantine suzerainty, he received a title of Curopalate (Greek: κουροπαλάτης) and established the Kouropalatate of Iberia. The Bagrationi family eventually took control of both Upper and Lower Tao and gradually expanded its sphere of influence. He encouraged resettlement of Georgians in these lands, and patronized monastic life initiated by the prominent Georgian ecclesiastic figure Grigol Khandzta (c. 759–861). For a long time the region became a cultural safe-house and one of the most important religious centers of Georgia. In the second half of the 10th century, Tao became a large and powerful principality during the rule of David III of Tao. The growth and consolidation of this principality contributed to the expansion of Georgian cultural and economic ties with other kingdoms and principalities. The might of the principality was clearly demonstrated in 979, when Byzantine Emperor Basil II, facing a large rebellion of Bardas Scleros (976–979), appealed for help to David III. Georgian expeditionary corps under the John Tornikios defeated the insurgents and restored the emperor's authority. Throughout his reign, David Curopalates pursued his grand design of the unification of Georgia. Supported by Ioane Marushisdze, the powerful duke of Iberia (Kartli), he succeeded in having his adopted son Bagrat placed on the throne of Kartli in 975 and of Abkhazia in 978. Following David III's death in 1001, his domain was inherited by emperor of Byzantine Basil II, these provinces were organized into the theme of Iberia with the capital at Theodosiopolis, forcing the successor Georgian Bagratid ruler Bagrat III to recognize the new rearrangement. Bagrat's son, George I, however, inherited a longstanding claim to David's succession. Young and ambitious, George launched a campaign to restore the Kuropalates’ succession to Georgia and occupied Tao in 1015–1016. Byzantines were at that time involved in a relentless war with the Bulgarian Empire, limiting their actions to the west. But as soon as Bulgaria was conquered, Basil II led his army against Georgia (1021). An exhausting war lasted for two years, and ended in a decisive Byzantine victory, forcing George to agree to a peace treaty, in which he had to abandon his claims to Tao. After the Battle of Manzikert in 1071 the Seljuk advance forced the Byzantines to evacuate the eastern Anatolia, in 1072-1073 the Georgian governor of "theme of Iberia," Gregory Pakourianos ceded control over Tao to King George II of Georgia.