 Umar undertook many administrative reforms and closely oversaw public policy, establishing an advanced administration for newly conquered lands, including several new ministries and bureaucracies, as well as ordering a census of all the Muslim territories.During his reign, the garrison cities of Basrah and al-Kūfah were founded or expanded.In 638, he extended and renovated the Grand Mosque in Mecca and the Mosque of the Prophet in Medina.