Gilles de Rais, one of the earliest known serial killers, is taken into custody upon an accusation brought against him by Jean de Malestroit, Bishop of Nantes.

Gilles de Rais, Baron de Rais was a knight and lord from Brittany, Anjou and Poitou, a leader in the French army during the Hundred Years' War, and a companion-in-arms of Joan of Arc. He is best known for his reputation and later conviction as a confessed serial killer of children.

A serial killer is an individual who murders three or more people, with the killings taking place over a period of more than one month in three or more separate events. Their psychological gratification is the motivation for the killings, and many serial murders involve sexual contact with the victims at different points during the murder process. The United States Federal Bureau of Investigation (FBI) states that the motives of serial killers can include anger, thrill-seeking, attention seeking, and financial gain, and killings may be executed as such. The victims tend to have things in common, such as demographic profile, appearance, gender, or race. As a group, serial killers suffer from a variety of personality disorders. Most are often not adjudicated as insane under the law. Although a serial killer is a distinct classification that differs from that of a mass murderer, spree killer, or contract killer, there are overlaps between them.

Jean de Malestroit was a pseudo-cardinal who served as Bishop of the Roman Catholic Diocese of Nantes from 17 July 1419 until 1443 AD when he resigned.

The Diocese of Nantes is a Latin Church diocese of the Catholic Church in Nantes, France. The diocese consists of the department of Loire-Atlantique. It has existed since the 4th century. It is now suffragan of the Archdiocese of Rennes, Dol, and Saint-Malo, having previously been suffragan to the Archdiocese of Tours. The seat of the bishop is the Cathedral of S. Pierre in the city of Nantes.