Thomas the Slav (, – October 823) was a 9th-century Byzantine military commander, most notable for leading a wide-scale revolt in 821–23 against Emperor Michael II the Amorian ().
An army officer of Slavic origin from the Pontus region (now north-eastern Turkey), Thomas rose to prominence, along with the future emperors Michael II and Leo V the Armenian (), under the protection of general Bardanes Tourkos. After Bardanes' failed rebellion in 803, Thomas fell into obscurity until Leo V's rise to the throne, when Thomas was raised to a senior military command in central Asia Minor. After the murder of Leo and usurpation of the throne by Michael the Amorian, Thomas revolted, claiming the throne for himself. Thomas quickly secured support from most of the themes (provinces) and troops in Asia Minor, defeated Michael's initial counter-attack and concluded an alliance with the Abbasid Caliphate. After winning over the maritime themes and their ships as well, he crossed with his army to Europe and laid siege to Constantinople. The imperial capital withstood Thomas's attacks by land and sea, while Michael II called for help from the Bulgarian ruler khan Omurtag. Omurtag attacked Thomas's army, but although repelled, the Bulgarians inflicted heavy casualties on Thomas's men, who broke and fled when Michael took to the field a few months later. Thomas and his supporters sought refuge in Arcadiopolis, where he was soon blockaded by Michael's troops. In the end, Thomas's supporters surrendered him in exchange for a pardon, and he was executed.
Thomas's rebellion was one of the largest in the Byzantine Empire's history, but its precise circumstances are unclear due to competing historical narratives, which have come to include claims fabricated by Michael to blacken his opponent's name. Consequently, various motives and driving forces have been attributed to Thomas and his followers. As summarized by the Oxford Dictionary of Byzantium, "Thomas's revolt has been variously attributed to a reaction against Iconoclasm, a social revolution and popular uprising, a revolt by the Empire's non-Greek ethnic groups, Thomas's personal ambitions, and his desire to avenge Leo V." Its effects on the military position of the Empire, particularly vis-à-vis the Arabs, are also disputed.
Early life and career
The 11th-century Theophanes Continuatus states that Thomas was descended from South Slavs resettled in Asia Minor by successive Byzantine emperors, while the 10th-century chronicler Genesios calls him "Thomas from Lake Gouzourou, of Armenian race". Most modern scholars support his Slavic descent and believe his birthplace to have been near Gaziura in the Pontus. Hence his epithet of "the Slav", which has been applied to him only in modern times. Nothing is known about his family and early life, except that his parents were poor and that Thomas himself had received no education. Given that he was between 50 and 60 years old at the time of the rebellion, he was probably born around 760.
Two different accounts of Thomas's life are recounted in both Genesios and Theophanes Continuatus. According to the first account, Thomas first appeared in 803 accompanying general Bardanes Tourkos, and pursued a military career until launching his revolt in late 820. In the second version, he came to Constantinople as a poor youth and entered the service of a man with the high court rank of patrikios. Then, discovered trying to commit adultery with his master's wife, Thomas fled to the Arabs in Syria, where he remained for 25 years. Pretending to be the murdered emperor Constantine VI (r. 780–797), he then led an Arab-sponsored invasion of Asia Minor, but was defeated and punished. Classical and Byzantine scholar J.B. Bury tried to reconcile the two narratives, placing Thomas's flight to the Abbasid Caliphate at around 788 and then having him return to Byzantine service before 803, while the Russian scholar Alexander Vasiliev interpreted the sources as implying that Thomas fled to the Caliphate at Constantine VI's deposition in 797, and that his participation in Bardanes's revolt must be discounted entirely. The second version of Thomas's story is explicitly preferred by Genesios and Theophanes Continuatus, and is the only one recorded in 9th-century sources, namely the chronicle of George the Monk and the Life of Saints David, Symeon, and George of Lesbos. Nevertheless, the French Byzantinist Paul Lemerle came to consider it an unreliable later tradition created by his rival Michael II to discredit Thomas, and rejected it altogether, preferring to rely on the first account alone. Most modern scholars follow him in this interpretation.