Shur?a (Arabic: ?) is the common Arabic term for police, although its precise meaning is that of a "picked" or elite force. Bodies termed shur?a were established in the early days of the Caliphate, perhaps as early as the caliphate of Uthman (644-656). In the Umayyad and Abbasid Caliphates, the shur?a had considerable power, and its head, the ib al-shur?a (Arabic: ? ), was an important official, whether at the provincial level or in the central government. The duties of the shur?a varied with time and place: it was primarily a police and internal security force and also had judicial functions, but it could also be entrusted with suppressing brigandage, enforcing the ?isbah, customs and tax duties, rubbish collection, acting as a bodyguard for governors, etc. From the 10th century, the importance of the shur?a declined, along with the power of the central government: the army--now dominated by foreign military castes (ghilm?n or mam?l?k)--assumed the internal security role, while the cities regained a measure of self-government and appropriated the more local tasks of the shur?a such as that of the night watch.