The Pickelhaube also written as Pickelhauben (plural) ;  Derived from the old German word Pickel = “point” or “pickaxe”, and Haube = “bonnet”, a general word for headgear), Pickelhelm is a spiked helmet worn in the 19th and 20th centuries by German military, firefighters, and police officers. Pickelhaube are typically associated with the Prussian army as were originally designed in 1842 by King Frederick William IV of Prussia, the helmet was widely imitated by other armies during this period later on. Frederick William IV introduced the Pickelhaube for use by the majority of Prussian infantry on October 23, 1842 by a royal cabinet order. The use of the Pickelhaube spread rapidly to other German principalities. Oldenburg adopted it by 1849, Baden by 1870, and in 1887, the Kingdom of Bavaria was the last German state to adopt the Pickelhaube.