The
Battle of Mu'tah was fought in September 629 near the village of
Mu'tah, east of the
Jordan River and
Karak, between the forces of Muhammad and
the forces of the
Byzantine Empire and their
Arab Christian Ghassanid vassals. In Islamic historical sources, the battle is usually described as the
Muslims' attempt to take retribution against the
Ghassanids after a Ghassanid official executed Muhammad's emissary who was en route to
Bosra. During the battle the Muslim army was routed. After three Muslim leaders (including Usama's father,
Zayd ibn Harithah), were killed, the command was given to
Khalid ibn al-Walid and he succeeded in saving the rest of the forces. The surviving Muslim forces retreated to
Medina. After the
Farewell Pilgrimage in 632, Muhammad appointed
Usama ibn Zayd as the commander of an expeditionary force which was to invade the region of
Balqa in the
Byzantine Empire. The stated aim of this expedition was to avenge the Muslim losses at the
Battle of Mu'tah, in which Usama's father and Muhammad's adopted son,
Zayd ibn Harithah, had been killed. Usama gathered a force of approximately 3000 men, of which 1000 were cavalry soldiers, and
Abu Bakr had intended on joining Usama on campaign. Usama had also sent spies ahead of him, from which he learned that the enemy were still unaware of the imminent approach of his army. However, due to Muhammad's death on 8 June, the campaign was delayed and
Abu Bakr was elected as
Caliph in
Medina. With the death of Muhammad, some Muslim leaders and citizens resisted going under the command of Usama because they thought that he, who was 20 at the time, was too young to lead an army. Muhammad dismissed these concerns. This incident is also mentioned in the
Sahih al-Bukhari. Certain
companions of the prophet tried to persuade
Abu Bakr, who succeeded Muhammad as leader of the Islamic community, to replace Usama as commander of the army with
Umar Ibn Al-Khattab, due to Usama's youth. Abu Bakr was under great pressure regarding this expedition due to rising rebellion and
apostasy across
Arabia, but he was determined. Abu Bakr reaffirmed the decision of Muhammad and dispatched the expedition with Usama as commander. == Expedition ==