Station sergeant (also known as Crown sergeant or Staff sergeant) is a police rank senior to sergeant and junior to inspector in some British and Commonwealth police forces. The rank insignia is usually a sergeant's three chevrons surmounted by a crown, or sometimes four chevrons. The Metropolitan Police (of London), which was the first force to introduce the rank, originally used four chevrons, but later changed to a crown over three chevrons. A police officer holding the rank will be the senior sergeant in a police station, or in some cases the commander of a smaller sub-divisional police establishment.