Garviel Loken became one of the leaders of the Loyalist factions of the Luna Wolves, Emperor’s Children, World Eaters and Death Guard Legions that refused to betray the Emperor of Mankind and serve the Ruinous Powers of Chaos. Later, he was recruited from the undead-haunted ruins of the Choral City on Istvaan III by his fellow Loyalist Space Marine Captain Nathaniel Garro, formerly of the Death Guard Legion, to serve as one of the 8 Astartes who founded the elite Grey Knights Space Marine Chapter of what later became the Inquisition.