Led by Harun al-Rashid at their height, for 10 points, name this Muslim Caliphate which ended with Hulagu Khan's sacking of their capital, Baghdad, who had earlier overthrown the Umayyads.
This entity faced the rebellion of the Qarmatians, an extremist Ismaili sect who desecrated the Well of Zamzam, and the earlier Zanj Rebellion helped Ahmad ibn Tulun found a rival kingdom to their west. Soon after the death of one of their leaders, this entity disintegrated into the Buyid, Idrisid and Aghlabid dynasties, but it was their victory at the Battle of the Zab over Marwan II which had earlier solidified their power. Led by Harun al-Rashid at their height, for 10 points, name this Muslim Caliphate which ended with Hulagu Khan's sacking of their capital, Baghdad, who had earlier overthrown the Umayyads.
This entity faced the rebellion of the Qarmatians, an extremist Ismaili sect who desecrated the Well of Zamzam, and the earlier Zanj Rebellion helped Ahmad ibn Tulun found a rival kingdom to their west.
{Abbasid} Caliphate [or al-Abbasiyun]