Participant in the First Crusade (1096-1099).
Peter was a younger son of Frederick I, count of Astenois, and Gertrude, daughter of Count Rainald II of Toul. He is sometimes wrongly referred to as if he originated from Stenay on the River Meuse. This error derives from a mistaken interpretation of one of the designations used for him in the Latin sources (Petrus de Stadeneis), which relates to his county of Astenois, a district of Champagne. His main stronghold wasDampierre-le-Château near Sainte-Menehould. He and his brother Rainald III, count of Toul, took part in the crusade in the army of their kinsman Godfrey of Bouillon, duke of Lower Lotharingia. He returned home in the summer of 1099.