63rd Expeditionary Fleet

The 63rd Expeditionary Fleet was one of the Imperium of Man's interstellar military expeditions sent out as part of the Emperor of Mankind's Great Crusade to reunite all the human-settled worlds of the Milky Way Galaxy under his rule during the 31st Millennium. It was commanded by the Primarch and Warmaster Horus of the Luna Wolves (later Sons of Horus) Space Marine Legion and formed the core of the Traitor forces that would challenge the Emperor for control of the Imperium during the terrible interstellar civil war known as the Horus Heresy.