Gilles de Rais' Closet Key

Origin
Gilles de Montmorency-Laval (1404–1440), Baron de Rais, was a Breton knight, a leader in the French army and a companion-in-arms of Joan of Arc. He is best known by his reputation and conviction as a prolific serial killer of children.

A member of the House of Montmorency-Laval, Gilles de Rais grew up under the tutelage of his maternal grandfather and increased his fortune by marriage. Following the War of the Breton Succession, he earned the favour of the Duke and was admitted to the French court. From 1427 to 1435, Gilles served as a commander in the Royal Army, and fought alongside Joan of Arc against the English and their Burgundian allies during the Hundred Years' War, for which he was appointed Marshal of France.

In 1434/1435, he retired from military life, depleted his wealth by staging an extravagant theatrical spectacle of his own composition and dabbled in the occult. After 1432 Gilles engaged in a series of child murders, his victims possibly numbering in the hundreds. The killings came to an end in 1440 when a violent dispute with a clergyman led to an ecclesiastical investigation which brought Gilles' crimes to light. At his trial the parents of missing children in the surrounding area and Gilles' own confederates in crime testified against him. Gilles was condemned to death and hanged at Nantes on 26 October 1440.

Gilles de Rais is believed to be the inspiration for the 1697 fairy tale "Bluebeard" by Charles Perrault. His life is the subject of several modern novels, and referenced in a number of rock bands' albums and songs.

Bluebeard
Bluebeard, believed to be inspired by Gilles, was a man who killed all of his wives and kid them in a closet. When he became engaged wit yet another woman, he left, giving her his closet key, telling her not to open the closet. She opens it, finding that it is filled with his dead previous wives, and drops the key on the bloody floor.