The post was created by the Metropolitan Police Act 1829 and was, until 1855, held jointly by two men. Until the 1970s, the Commissioners were justices of the peace and not sworn constables. The title commissioner was not used until 1839.
A Commissioner is always knighted on appointment if he has not already been (many of the Deputy Commissioners are also knighted). The insignia of rank is a crown above a Bath Star ("pip") above crossed tipstaves within a wreath, very similar to the insignia worn by a full general in the British Army. This badge is almost unique within the British police, shared only with the Commissioner of the City of London Police.
At one time, the commissioners were either retired military officers or civil servants. Sir John Nott-Bower was the first career police officer to hold the post (although several previous commissioners had served in senior administrative positions in colonial forces and the Metropolitan Police itself) and Sir Joseph Simpson was the first commissioner to have started his career as a constable (although he was soon appointed to higher rank). However, Sir Robert Mark, appointed in 1972, was the first to have risen through all the ranks from the lowest to the highest, as all his successors have done.