Zanj Rebellion
The Battle of Basra was a major engagement of the Zanj Rebellion, fought on September 7–10, 871. Zanj rebels and allied Arab tribesmen, led by Yahya ibn Muhammad al-Azraq and 'Ali ibn Aban al-Muhallabi, launched a coordinated attack against the city of Basra. The city’s defenders, consisting of a small contingent of Abbasid regular troops and local Basran militia, were quickly overwhelmed, and the Zanj were able to enter the city, after which they massacred its inhabitants and engaged in a several-day period of looting.