The siege of Theodosiopolis occurred in August 502, during the opening stages of the Anastasian War. The Sasanian ruler Kavadh I laid siege to the city of Theodosiopolis, a major Byzantine stronghold in western Armenia.

The chronicler Joshua the Stylite wrote in 507 that the general Constantine rebelled against emperor Anastasius I Dicorus, and then surrendered Theodosiopolis to the Sasanians. Joshua then writes that "Kawad (Kavadh I) consequently plundered the city, and destroyed and burned it; and he laid waste all the villages in the region of the north, and the fugitives that were left he carried off captive." Kavadh I then promoted Constantine general, before marching on.

After the successful siege, Kavadh I besieged other Byzantine cities, such as Amida.

• Greatrex, Geoffrey; Lieu, Samuel N. C. (2002). The Roman Eastern Frontier and the Persian Wars (Part II, 363–630 AD). New York and London: Routledge (Taylor & Francis). pp. 62–63. ISBN 0-415-14687-9.

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