Eugène de Beauharnais’ first promotion Signed by Alexandre Berthier - 1798 This is the official document promoting Joséphine’s son, Eugène de Beauharnais, to Lieutenant and Aide de Camp to Napoléon. It is signed by General Louis Alexandre Berthier, Napoléon’s chief of staff, in Cairo. This was Eugène’s first promotion. He was later to become Viceroy of Italy and regularly fight at his stepfather’s side.