Tao () is a historical region of Georgia and forms part of the wider historical area of Tao-Klarjeti. Geographically, the region lay in the middle basin of the Çoruh River and broadly corresponded to the historical Armenian province of Tayk. In modern administrative terms, its territory largely overlaps with the Yusufeli district of Artvin Province, as well as several northern districts of Erzurum Province, including Uzundere, Olur, Oltu, Şenkaya, Narman, and Tortum.
Name The name of the region preserves the ethnonym of the ancient tribe known as the Taochi, who inhabited this area in antiquity.
Earlier forms of the name appear as Diauehi or Daiaeni, which are attested in Assyrian cuneiform inscriptions of the 12th–9th centuries BC and in Urartian inscriptions of the 9th–8th centuries BC.
After the 760s BC, the name Diauehi disappears from written sources; however, it is widely considered to have survived in later ethnonyms and toponyms, including Tao in Georgian tradition, Taochi in Greek sources, and Daikh or Tayk in Armenian historiography.
History
Early period
According to the studies of Nikolai Marr, the Chans originally occupied a much wider territory, including the Çoruh River basin and its right-bank tributaries, from which they were temporarily displaced—first by Armenians and later by Georgians. According to Ivane Javakhishvili, from ancient times Tao and the neighboring region of İspir were inhabited by Georgian tribes of Laz or Chalybes. By contrast, Igor M. Diakonoff proposed that the earliest population of the region may originally have been Hurrian-speaking and was later gradually Kartvelianized (more precisely, Chanized), after which the area became a zone of intensive Armeno–Chan interaction.
The region and its inhabitants—most notably the Chalybes, Taochi, and Phasians—are described in the Anabasis of Xenophon, who passed the area with the Ten Thousand in the 4th century BC. Based on this account, Robert W. Edwards concluded that the Taochi most likely inhabited the valleys of Oltu, Narman, and Tortum. At that time, like the Carduchii and Chaldians, they were a free people not subject to Persian rule, although they later came under the authority of the Iberians.
According to Cyril Toumanoff, by the 4th–3rd centuries BC the region had already become part of the ancient Georgian Kingdom of Iberia. According to Geography of Strabo (XI.14.5), in the early 2nd century BC the area was seized by Artaxiad Armenia from Iberia. Although Strabo refers specifically to the ("the slopes of the Paryadres"), modern scholarship generally identifies this area with the historical region of Tao.
From the late 4th to the 8th centuries: the Mamikonian period
At some point during Late Antiquity, Tao became an appanage of the Armenian noble house of the Mamikonian. According to Robert W. Edwards, the Mamikonians were Kartvelian origin, deriving from the Chan tribe. Cyril Toumanoff similarly suggested that they originated either from the Chans or from the Laz. Over time, the Chans were gradually absorbed into the Mamikonian principality. The residence of the Mamikonian branch ruling Tao was located at the fortress of Erahani, the precise location of which remains unknown.
Armenian sources allow the history of the Mamikonian family to be traced from the early 4th century AD onward. Their integration into Armenia and the gradual incorporation of Tao into the Armenian political sphere occurred through military alliances, dynastic marriages, and the acquisition of hereditary offices granted by the Armenian monarchy.
According to Nina Garsoïan, Tao-Tayk may have been evangelized as early as the time of Gregory the Illuminator. An Arabic translation of the 5th-century historian Agathangelos recounts how Gregory sent bishops to Basiani, Speri, and Kola, in later interpretations, this reference to Kola has sometimes been understood as extending to Tao as well. However, Armenian sources only from the late 6th century, following the peace of 591, provide the earliest clear evidence for treating Tao-Tayk and Kola collectively under a single regional name. Georgian ecclesiastical tradition attributes the earliest missionary activity in Tao to Andrew the Apostle, who is said to have preached in the "lands of Kartli". According to The Georgian Chronicles, after performing miracles in Samtskhe and leaving an icon of the Virgin Mary there, Andrew continued his mission into Tao. Persian rule and ecclesiastical division
Following the Partition of Armenia in 387, Tao fell within the Persian sphere of influence, while its western frontier functioned as a border zone between the Byzantine Empire and the Sasanian Empire. This frontier represented not only a political boundary but also an ideological divide between Christianity and Zoroastrianism.
Tao-Tayk remained within the boundaries of the Armenian kingdom—later reduced to a Sasanian vassal—and subsequently within the Marzpanate of Armenia After the extinction of the Armenian royal line in 428, the Mamikonian family—whose principal rivals were the Bagratuni—pursued an increasingly independent foreign policy, alternately aligning with Byzantium or Persia.
In 450, Tao participated in the Armenian uprising against Persian rule, culminating in the Battle of Avarayr. During the revolt in Tao-Tayk, mountaineers from Chaldia joined local guerrilla forces to oppose Persian columns advancing toward the Byzantine frontier. Leadership of the local resistance was assumed by Amayak Mamikonian, together with Arten Kabelean and Varaz-Shapuh Paluni; the movement was ultimately suppressed by Vasak Siwni, who led a Persian punitive expedition in the region.
According to Robert W. Edwards, during the Artaxiad and Arsacid periods, as well as under Persian suzerainty (c. 387–591), the northwestern boundary of Tao extended to the Çoruh River, where the population was likely predominantly Georgian. Robert H. Hewsen similarly argued that during the Mamikonian period Tao and Kola were largely Georgian districts, while Bolkha and its surrounding districts may have been predominantly Armenian. Both Edwards and Hewsen criticized nationalist interpretations portraying Tao-Tayk as solely Armenian or Georgian.
The acts of the Second Council of Dvin (555) constitute the last known historical document to mention an Armenian bishop from Tao-Tayk. According to Nikoloz Aleksidze, by the late 6th or early 7th century Tao had adopted the Chalcedonian tradition and ceased to fall under the authority of the Armenian Church of Persarmenia, suggesting possible Georgian ecclesiastical jurisdiction over the region during this period.
Byzantine influence and Arab invasions As a result of the Byzantine–Sasanian War of 572–591, Emperor Maurice reorganized Armenia, bringing Tao under Byzantine control in 591. According to Cyril Toumanoff, Tao-Tayk became part of the Byzantine province known as Deep Armenia (Armenia Profunda), which consisted of three districts. This view, however, is not universally accepted: Robert Edwards argues that there is no clear evidence that Tao-Tayk itself was ever formally renamed Deep Armenia. Nina G. Garsoian observes that Armenian sources following the peace of 591 provide the earliest evidence for treating Tao, Kola, and Bolkha as a single, unified region under a common name — Tayk. Moreover, as noted by Hewsen, before the Byzantine reorganization Kola may have existed as a separate principality rather than as an integral part of Tayk.
Following the military campaigns of Emperor Heraclius during the subsequent Byzantine–Sasanian War of 602–628, the Kingdom of Iberia lost the coastal territory of Klarjeti—including the cantons of Nigali and Murguli in the lower Çoruh basin—as well as the "land of Tukharis", which was incorporated into Tao.
At least part of Tao appears to have been granted as an appanage to a cadet branch of the Mamikonian family in the 6th century. Between the 6th and 7th centuries, the secondary branch of the Dimaksian dynasty, based in eastern Tao, established the independent principality of Bolkha/Bukha (known in Georgian sources as Bugatakuri). Northeast of Bolkha was the principality of Kola, governed by local native rulers bearing the same name. The Mamikonians, the Dimaksians, and other lesser independent or semi-independent feudal lords in the region maintained their own armed retinues and banners. According to the Zoranamak (military list), Tao-Tayk was credited with maintaining a military retinue of approximately 1,000 retainers, although the source does not explicitly mention the presence of the Mamikonians in the region.
In 607, the Third Council of Dvin condemned the Council of Chalcedon and the Tome of Leo. As a result, a number of Chalcedonian dissidents migrated either to Tao—which lay within the Iberian political sphere—or to the Byzantine Empire. Bishops who refused to submit to the authority of Catholicos Abraham sought refuge in Tao thus escaped the jurisdiction of the Catholicosate of Dvin, as Tao lay outside Persian territory. According to Gérard Garitte, these clerics may have been more closely dependent on the Georgian Church than on the Armenian Church.
Following the Arab conquests of the South Caucasus, the emirate of Arminiya was established and administratively divided into four regions. In Arabic sources, Tao was known as Sirāj Ṭayr and formed part of either Arminiya III or Arminiya II. From the mid-7th century until 772, the Mamikonians ruled Tao under the suzerainty of the Arab Caliphate. The Arab invasions of the 7th century marked the collapse of the traditionally pro-Byzantine Mamikonians, who ultimately lost most of their lands and political influence.
The Armenian Catholicos Nerses III the Builder spent six years in exile in Tao-Tayk after leaving Dvin in 654. Under Byzantine rule, two major churches were constructed at Bana and Ishkhani; the church at Ishkhani was founded by Nerses III himself. Both churches were destroyed following the Arab invasions. In the early 9th century, they were restored and converted into episcopal centers by Georgian clerics Saba of Ishkhani and Kvireke of Bana.
During the 8th century, the region was devastated twice: first in 735 during the campaign of the Arab general Marwan II, and again in 774–775 during an anti-Arab uprising. The failure of this revolt had catastrophic consequences for the Mamikonians, who lost Tao—largely to the Bagratuni and partly to Iberia.
In the 770s, Ashot Msaker subdued Shirak and Abotsi and advanced into Tao, where he built the fortress of Kalmakhi and made it his residence. According to René Grousset, Ashot played a role in the Armenization of the borderlands by settling colonists from Aliovit and Arsharunik in the ethnically contested province of Tao-Tayk, which remained under strong Iberian and Byzantine influence. During this period, the Armenian Gnuni family also settled in Tao.
From the 8th to the 10th centuries: the rise of the Iberian Bagratids
According to Cyril Toumanoff, after 772 Tao-Tayk, which at that time belonged to the Mamikonian family, was divided into two parts. Upper Tao was acquired by the Bagratids, while Lower Tao, together with Asispori, passed to the Guaramids. Between approximately 786 and 807, Lower Tao—together with Asispori in Upper Tao—came under the control of the Iberian Bagratids. By 813, Tao was fully reunified. From this point onward, the region shifted from the Armenian political sphere into the Georgian one.