Before the creation of the first Space Marine Legions, the Legiones Astartes were organised into a formation known as the "Six Hosts of the Angels of Death", with each of these Hosts having its own specialisation and purpose. During the Wars of Unification the Six Hosts had each been created by the Emperor for a specific task, or from a particular type of warrior. Their names, if they had any, were unknown by the second century of the Great Crusade. These Hosts did not fight alone, being too specialised for general warfare on Terra and during the initial stages of the Great Crusade. Instead, elements of each Host were combined into battle groups of different sizes and designations. As and when required, the Hosts provided their troops to these armies depending upon the military need.