Gilles de Rais (c. 1405 – 26 October 1440), Baron de Rais (də ʁɛ), was a knight and lord from Brittany, Anjou and Poitou, a leader in the French army, 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 member of the House of Montmorency-Laval, Gilles de Rais was raised by his maternal grandfather. He earned the favour of the Duke of Brittany and was admitted to the French court. From 1427 to 1435, Rais served as a commander in the French army, and fought in the Hundred Years' War, for which he was appointed Marshal of France.
Rais is sometimes believed to be the inspiration for the French folktale "Bluebeard" ("Barbe bleue"), but this assumption is controversial.
On 30 November 1420, Craon did substantially increase his grandson's fortune by marrying him to Catherine de Thouars of Brittany, heiress of La Vendée and Poitou. Their only child, Marie, was born in 1433 or 1434.
In the decades following the Breton War of Succession (1341–64), the defeated faction led by Olivier de Blois, Count of Penthièvre, continued to plot against the Dukes of the House of Montfort. The Blois faction, which refused to relinquish its claim to rule over the Duchy of Brittany, had taken Duke John VI prisoner in violation of the Treaty of Guérande (1365). Jean de Craon took the side of the House of Montfort. After the Duke's release, Jean de Craon and his grandson Gilles de Rais were rewarded for their "good and notable services" with generous land grants that were converted to monetary gifts.
In 1425, Rais appeared in the entourage of king Charles VII at Saumur, but he might have been introduced to the royal court before this date. At the battle for the Château du Lude, he killed or took prisoner the English captain Blackburn.
From 1427 to 1435, Rais served as a commander in the Royal Army, fighting in the Hundred Years' War. In 1429, he fought alongside Joan of Arc in some of the campaigns waged against the English and their Burgundian allies.