Battlefleet Calixis officially came into being in 384.M39, a result of the Calyx Expanse being conquered during the Angevin Crusade. A half-dozen ships left over from the Crusade stayed behind and consolidated Imperial holdings in the area. That same year, the Battlefleet saw its first action against the Yu'vath, a powerful and dangerous Xenos race. Though they took heavy losses, with the help of the Iron Hands Space Marine Chapter, the Battlefleet emerged victorious over the aliens and traitor allies.
- Fist of Adamant — A Retribution Class Battleship and flagship of the Battlefleet
- Triumph of Saint Drusus — A Chalice Class Battlecruiser