The siege of Dara was raised by the Sasanian king Khosrow I in 573 during the Byzantine–Sasanian War of 572–591. The fortified city fell after 4 months. The Sasanians cut through a hill to divert the city's water supply, and used captured Roman ballistae from the abandoned Roman Siege of Nisibis (573). The news of the fall of Dara, long a major Byzantine stronghold in Upper Mesopotamia, contributed to Emperor Justin's mental health decline. Bahram Chobin was commander of the cavalry force in the siege, and was promoted to the Spahbed of the North after this victory.
References
== Sources == http://www.iranicaonline.org/articles/dara-the-name-of-a-parthian-city-and-of-a-byzantine-garrison-town-of-the-sasanian-period 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. 142–153. ISBN 0-415-14687-9. Martindale, John R., ed. (1992). The Prosopography of the Later Roman Empire: Volume III, AD 527–641. Cambridge: Cambridge University Press. ISBN 0-521-20160-8. Nicholson, Oliver; Canepa, Matthew; Daryaee, Touraj (2018). "Khosrow I Anoshirvan". In Nicholson, Oliver (ed.). The Oxford Dictionary of Late Antiquity. Oxford: Oxford University Press. ISBN 978-0-19-866277-8. Shahbazi, A. Sh. (1988). "Bahrām VI Čōbīn". Encyclopaedia Iranica, Vol. III, Fasc. 5. London et al. pp. 514–522.{{cite encyclopedia}}: CS1 maint: location missing publisher (link) Whitby, Michael; Whitby, Mary (1986). The History of Theophylact Simocatta. Oxford, United Kingdom: Clarendon Press. ISBN 978-0-19-822799-1.
