The siege of Ankara was an inconclusive siege of Ankara by Timur.
From Sivas, Timur's army marched to Ankara in twelve days.
The lead contingents of Timur's army encountered a force led by Yakub Bey and defeated them.[1] Timur arrived later with the main force.[1]
The Ottoman sultan, Bayezid, informed of Timur's invasion, raised his siege of Constantinople and forced marched his army toward Ankara.[2]
Upon hearing Bayezid's army was nine miles away, Timur, whose temporary siege had consisted of diverting the city's water supply and undermining the city walls, quickly moved his army into defensive positions behind a ditch.[3] It was from this defensive position Timur waited for Bayezid to attack.[3]
Cross, Toni Marie; Leiser, Gary (2000). A Brief History of Ankara. Indian Ford Press.
Roemer, H.R. (1986). "Timur in Iran". In Fisher, W. B.; Jackson, Peter; Lockhart, Lawrence; Gershevitch, Ilya (eds.). The Cambridge History of Iran. Vol. 6: The Timurid and Safavid Periods. Cambridge University Press.
Pears, Edwin (1923). "The Ottoman Turks to the Fall of Constantinople". In Bury, J.B.; Tanner, J.R.; Previte-Orton, C.W.; Brooke, Z.N. (eds.). The Cambridge Medieval History. Vol. IV: The Eastern Roman Empire. Cambridge University Press.