Bardanes, nicknamed Tourkos, "the Turk" (Greek: Βαρδάνης ὁ Τοῦρκος, romanized: Varthanis o Tourkos, fl. 795–803), was a Byzantine general who launched an unsuccessful rebellion against Emperor Nikephoros I (r. 802–811) in 803. Although a major supporter of Byzantine empress Irene of Athens (r. 797–802), soon after her overthrow he was appointed by Nikephoros as commander-in-chief of the Anatolian armies. From this position, he launched a revolt in July 803, probably in opposition to Nikephoros's economic and religious policies. His troops marched towards Constantinople, but failed to win popular support. At this point, some of his major supporters deserted him and, reluctant to engage the loyalist forces in battle, Bardanes gave up and chose to surrender himself. He retired as a monk to a monastery he had founded. There he was blinded, possibly on Nikephoros's orders. He was of Turkic origin.
Nothing is known of the early life of Bardanes, and his origin is disputed. On account of his first name—a Hellenized form of the common Armenian name Vardan—some scholars consider him to have been of Armenian origin, whilst his sobriquet Tourkos, could suggest a Khazar origin. The Byzantinist Warren Treadgold, judging from both his name and epithet, speculates that he may have been of mixed Armenian and Khazar blood, an opinion shared by the historian Jean-Claude Cheynet. Cheynet suggests that the Khazar parentage belonged to a member of the entourage of Empress Irene of Khazaria, the wife of Emperor Constantine V (r. 741–775), and hence a certain proximity of Bardanes to the imperial court.
Bardanes is probably identical with the patrikios Bardanios who appears in the Chronicle of Theophanes the Confessor in the mid-790s. In 795, he was Domestic of the Schools (commander of the Scholai guard regiment), and was dispatched to arrest the monk Plato of Sakkoudion for his public opposition to the second marriage of Emperor Constantine VI (r. 780–797) to Plato's niece Theodote. In 797, as strategos (military governor) of the Thracesian Theme, this same Bardanios supported the Empress-mother Irene of Athens when she usurped the throne from her son. On Easter Monday, 1 April 799, he is recorded as one of the four patrikioi (along with Niketas Triphyllios, Sisinnios Triphyllios and Constantine Boilas) who led the horses of the Empress's carriage on a unique triumphal procession from the palace to the Church of the Holy Apostles.
Irene herself was overthrown and exiled by the logothetes tou genikou (finance minister) Nikephoros on 31 October 802. At the time, Bardanes was still patrikios and strategos of the Thracesians, but was soon transferred to command the powerful Anatolic Theme. In the next year, probably in preparation for a campaign against the Arabs following Nikephoros' refusal to continue the annual payment of tribute to the Abbasid Caliphate, the emperor apparently appointed Bardanes to the post of monostrategos (lit. 'single-general', in effect commander-in-chief) of the Empire's five Anatolian land themes, a position only conferred in exceptional cases. However, this appointment is by no means certain; he is mentioned as monostrategos only by later sources, while near-contemporary ones mention him only as strategos of the Anatolics. It is possible that later sources misinterpreted his title to mean "general of all the East" (Anatole in Greek).
In July 803, an Abbasid army under al-Qasim, a son of Caliph Harun al-Rashid (r. 786–809), began advancing towards the Byzantine frontier. As Nikephoros had broken his foot in early May, it fell to Bardanes to lead the Byzantine army against the Arabs. He therefore ordered the thematic armies of Anatolia assembled in the Anatolic Theme. On 19 July, Bardanes was proclaimed emperor by the assembled troops of the Anatolic, Opsician, Thracesian and Bucellarian themes. Crucially, the Armeniac Theme, either because of its traditional rivalry with the Anatolics, or because it had not yet joined up with the rest of the army, did not join the uprising. It has also been hypothesized that Bardanes may have participated in the suppression of the Armeniacs' revolt in 793, leaving lingering hostility towards him amongst its troops. Among the Byzantine chronicles that report on Bardanes's revolt, the 10th-century Theophanes Continuatus and the 13th-century Synopsis Chronike indicate that the troops were motivated chiefly by economic concerns. Nikephoros had initiated a strict budgetary policy to shore up the Empire's finances. The Emperor had revoked the exemption on inheritance tax for the soldiers, and had apparently left them unpaid for some time as well. Bardanes, on the other hand, had a good reputation in this regard, fairly dividing the booty won from the campaigns against the Arabs amongst the soldiers.
For the motives of Bardanes himself, the situation is less clear. According to the Byzantine chroniclers, he accepted the acclamation only reluctantly, after vainly entreating the soldiers to allow him to leave. According to another story however, before his revolt, Bardanes, accompanied by his three principal associates, Thomas the Slav, Leo the Armenian and Michael the Amorian visited a holy man at Philomelion to learn of the prospects for the uprising. The monk correctly prophesied that his rebellion would fail, that Thomas too would begin a revolt, and that Leo and Michael would reign as emperors. Although possibly a later invention, this story may suggest that Bardanes planned his revolt beforehand. Aside from any personal ambition, Bardanes was also a member of the landed aristocracy and a devoted iconophile who supported Empress Irene's regime. He has therefore also been seen as the representative of the opposition by the traditional elites to Nikephoros's policies, both in the confessional area, where the Emperor maintained a carefully neutral stance towards both iconoclasts and iconophiles, and in the socio-financial sphere, where new taxes on landed property and the expropriation of ecclesiastical estates hurt their interests. Treadgold further suggested that the revolt was a reaction against Nikephoros' usurpation and aimed, at least ostensibly, at the restoration of Irene. However, her death at Lesbos on 8 August deprived the rebels of any claim to legitimacy.
The revolt probably took place at Amorion, the capital of the Anatolic Theme. From there, the rebel army, comprising almost half of the Empire's available military forces, marched north and west, following the military road to Nicomedia and then to Chrysopolis, the town that lay across the Bosporus from the imperial capital, Constantinople. There, Bardanes encamped for eight days, awaiting a possible uprising against Nikephoros inside the capital in response to his own rebellion. Since this did not materialize, and the populace proved not overtly enthusiastic, he withdrew to the great army base at Malagina. There, two of his associates, Michael the Amorian and Leo the Armenian, abandoned him, and were richly rewarded by Nikephoros for their defection: Michael became Count of the Tent to the Emperor, and Leo was appointed commander of the Foederati regiment.
This desertion further discouraged Bardanes, and, reluctant to face the loyalist army in battle, he opted for a negotiated surrender through the mediation of Joseph, the hegumenos (abbot) of the Kathara monastery who had officiated at Constantine VI's second marriage. Bardanes received a letter signed by the Patriarch Tarasios and several leading senators which guaranteed that neither he nor his subordinates would be punished if they surrendered. As a further guarantee of good faith, Nikephoros sent his own gold cross along with the letter. Satisfied by these assurances, on 8 September Bardanes left his army and, through Nicaea, sought refuge in the monastery of Herakleios at Cius. From there, he embarked on a ship that took him to the island of Prote. Taking the monastic name Sabbas, Bardanes then entered a monastery that he had founded there in the past.