In the 4th and 5th centuries AD, following the Byzantine–Persian partition of Armenia in 387, Tao came under Persian influence, and its western border (Iberian gates) served as aboundary between the two empires.

The rise of the new dynasty was made possible by the extinction of the Guaramids and the near-extinction of the Chosroids, and also by the Abbasid preoccupation with their own civil wars and conflict with the Byzantine Empire.

The new era began in Tao-Klarjeti in 813, when the last Iberian prince Ashot I of the Bagrationi dynasty moved to Klarjeti and made it a base in his struggle against the Arab occupation.

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.

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.

After the Russian annexation of Georgia in 1801, the region was contested between Russia and the Ottoman Empire in a series of wars throughout the 18th and 19th centuries.

More importantly, the region contains numerous Georgian historical monuments, notably the churches and monasteries of Ishkhani, Bana, Doliskana, Parkhali, Kakhuli, Oshki, Otkhta and others.

Recent study has found most of the surviving monuments in satisfactory condition, but some have been vandalized, and immediate conservation and renovation is urgently needed.