Primitive ancestors of the guillotine were used in Ireland, England and Italy in the 14th and 15th Centuries. Several known decapitation devices such as the Italian Mannaia, the Scottish Maiden, and the Halifax Gibbet are well documented and may pre-date the use of the French guillotine by as much as 500 years.
This excerpt from La Révolution française (1989) shows Louis XVI receiving a demonstration of the guillotine from its creator. The story of the king suggesting an angled blade is apocryphal.
A guillotine is an apparatus designed for efficiently carrying out executions by beheading. The device consists of a tall, upright frame in which a weighted and angled blade is raised to the top and suspended. The condemned person is secured with stocks at the bottom of the frame, positioning the neck directly below the blade. The blade is then released, to quickly fall and forcefully decapitate the victim with a single, clean pass so that the head falls into a basket below.
Guillotine, instrument for inflicting capital punishment by decapitation, introduced into France in 1792. The device consists of two upright posts surmounted by a crossbeam and grooved so as to guide an oblique-edged knife, the back of which is heavily weighted to make it fall forcefully upon (and slice through) the neck of a prone victim.