Commander of the Infantry at the Conquest fo Mecca

Hazrat Abu Hurairah (ra) relates that on the day of the Conquest of Mecca, the Holy Prophet (sa) arrived into the city. The Holy Prophet (sa) appointed Hazrat Zubair (ra) and Hazrat Khalid (ra) bin Waleed to oversee each flank of the army and Hazrat Abu Ubaidah (ra) was appointed as the commander of the infantry and also of those who were entering through the low pass of the valley.

(Sahih Muslim, Kitab al-Jihad, Bab Fath Makkah, Hadith 1780)