Tao (historical region) in the context of "Zemo Kartli"

The Kingdom of the Iberians (Georgian: ქართველთა სამეფო, romanized: kartvelta samepo) was a medieval Georgian monarchy under the Bagrationi dynasty which emerged circa 888 AD, succeeding the Principality of Iberia, in historical region of Tao-Klarjeti, or upper Iberia in north-eastern Turkey as well parts of modern southwestern Georgia, that stretched from the Iberian gates in the south and to the Lesser Caucasus in the north.

Historically, the area comprised the following historical districts: West of the Arsiani Mountains were Tao, Klarjeti, Nigali, and Shavsheti, to the east lay Meskheti, Erusheti, Javakheti, Artaani, Abotsi, Kola and Basiani. The landscape is characterised by mountains and the river-systems of the Çoruh and the Kura. The region played a crucial role in the unification of all Georgian lands and principalities into the Kingdom of Georgia in 1008.

Tao-Klarjeti (Georgian: ტაო-კლარჯეთი, romanized: t'ao-k'larjeti [tʼäo̞kʼɫäɾd͡ʒe̞t̪ʰi]) is a Georgian historical and cultural region in north-eastern Turkey. The region is based around two river basins - Chorokhi and Kura (Mtkvari), and also partially includes the upper source of the Aras river. In modern usage it most often denotes the territory that was administered or claimed by Georgian Democratic Republic but is nowadays part of Turkey due to the Soviet-Turkish deal in 1921.

The term "Tao-Klarjeti" is based on the names of two most important provinces of the region — Tao and Klarjeti. The term is equivalent to “Zemo Kartli” (i.e., Upper Kartli or Upper Iberia) and is also a synonym for historical Meskheti.

Klarjeti (Georgian: კლარჯეთი [kʼlaɾd͡ʒetʰi]) was a province of ancient and medieval Georgia, which is now part of Turkey's Artvin Province. Klarjeti, the neighboring province of Tao and several other smaller districts, constituted a larger region with shared history and culture conventionally known as Tao-Klarjeti.

Adarnase IV (Georgian: ადარნასე IV) (died 923), or Adarnase II, was a Georgian monarch of the Bagrationi dynasty who reigned in the late 9th and early 10th centuries. The son of the Kouropalates David I of Iberia, he ruled as duke of Lower Tao from 881 to 923, king (mepe) of the Kingdom of the Iberians from 888 to 923 and Kouropalates of Iberia from 891 to 923, re-establishing the Georgian monarchy in 888, more than three centuries after the abolition of the Kingdom of Iberia by Sasanian Empire.

He succeeded his father to the duchy of Lower Tao, a border march between Byzantine Empire and Caucasus, when the latter was assassinated by Nasra of Tao-Klarjeti in 881. When the latter led a Byzantine invasion force to invade the Caucasus, Adarnase defeated him in 888 and became the first sovereign to take the title of ‘King of the Iberians’, to signal his independence from the Byzantine Empire. With the help of neighbouring Armenia, he consolidated his power and gained control over Kartli, as well as Byzantine recognition in 891 after killing Gurgen I of Tao. The reign of Adarnase IV was marked by a change in Georgia's political orientation, as it left the Byzantine sphere of influence to join Armenia and, by extension, a declining Abbasid caliphate. The king often became involved in Armenia's internal affairs and helped King Smbat I of Armenia to consolidate his own power.