Beheadings
Used: Everywere
First documented: Unknow
Death by beheading was fastest with a sharp sword comparative to a blunt ax. Though beheading were done before 1066 it wasn't till William the Conqueror used it as a judicial reasons.
The Guillotine is still the most iconic beheading instrument today though it wasn't created till 1785. The French colonies had the Guillotine till 1946 when it left the persion "Devil island".