Ertso-Tianeti was historically part of the saeristavo (duchy) of Kakheti. According to Georgian tradition and accounts from the 11th century, Saint Nino converted the inhabitants of the region to Christianity along with the rest of Iberia, c. 330. Due to its geographical location, Ertso-Tianeti was a region of great strategic and economical significance during the Middle Ages. It was traversed by a branch of the commercial road joining Kartli with Caucasian Albania and Armenia. During this period (6-9th centuries), Tianeti served as the foothold from which the lords of Kartli extended their political and cultural influence over the Greater Caucasus. During the struggle for unification of Georgia (10th century), the Kingdom of Abkhazia used the conquest of Tianeti to bring Kakheti into their allegiance.