The Forty-five guards were recruited by the Jean Louis de Nogaret de La Valette, Duke of Épernon to provide Henry III of France with trusted protection in the midst of the War of the Three Henrys.
The Forty-five were noblemen of lesser nobility (many from Gascony) with little more than a horse, a sword, and a few acres to live on. In the king's service, they were paid a lavish wage (by their standards). In return, 15 of them were to be on duty, day or night, ready at the king's call.
After the Catholic League revolt in Paris, King Henry III was forced to flee to Blois, there, he staged a coup, regaining control of the Estates-General by employing the Forty-five to kill Henry I, Duke of Guise when he came to meet the king at the Château de Blois on 23 December 1588, and his brother, Louis II, Cardinal of Guise, the following day.