The custodian helmet is the modern name applied to the helmet worn by male police officers in England and Wales (and formerly in Scotland) and certain other places around the world. It is synonymous with the "bobby on the beat" image.
The custodian helmet is the headgear traditionally worn by male police constables and sergeants while on foot patrol in England and Wales. Officers of all ranks in most forces are also issued a flat, peaked cap that is worn on mobile patrol in a vehicle. Ranks above sergeant wear the peaked cap only.
It was first adopted by the London Metropolitan Police in 1863 to replace the "stovepipe" top hat worn since 1829. In 1863, the Metropolitan Police replaced the previous uniform of white trousers, swallow-tailed coat and top hat in favour of very dark blue trousers, a more modern button up tunic and the early type of helmet which had an upturned brim at the front and a raised spine at the back, running from the bottom to the top of the helmet, which became known as the "cockscomb".
The early Metropolitan Police helmet had a "garter" style badge on the front of the helmet which had the officer's personal number and divisional letter in the centre, backed by a leather insert. This was surrounded by a wreath design which had the words "Metropolitan Police" around the outside and was topped with the reigning monarch's crown. This style changed in 1875, when an early version of the brunswick star was adopted without the upturned brim seen in the previous style. There was much variety in the style of helmets during this period. The form of the helmets gradually converged with the "foreign service" and "home service" helmets adopted by the British army in the late-1870s.
During the 1930s, the Home Office attempted to standardise the design of the helmets with the "Home Office Pattern", after it became evident that since the Metropolitan Police had adopted it and produced their own badge, many small county and borough police forces followed suit and individually adopted their own style badges and designs, which led to many different styles and designs. Some forces adopted the helmet without any badge, others designed their own, usually with the county's arms or crest in the centre. One force adopted an Australian style bush hat and one wore a helmet constructed of straw.