Hexagrammaton - History: Before the creation of the Ist Legion, each of the Legiones Astartes were organised instead 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 Terran 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 ever 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.The warriors of each host could be called upon when a particular threat or situation presented itself. The leader of a host, elected by his sect-brothers rather than appointed by the Emperor in those times, would assume temporary command of a battle or campaign so that their expertise could be deployed fully.It is not fully understood what happened to the Hexagrammaton in the other Legions and why its structure persisted only within the Ist Legion. For reasons only He knows, the Emperor chose not to continue with the Six Hosts and instead created the Principia Belicosa to structure the Legiones Astartes along the tactical lines which are now most familiar. The old ties of the brotherhoods continued in the  Ist Legion, though, and so the Six Hosts persisted in name and function. Being created from scratch, the later Legions were never built upon this foundation.Following the  Ist Legion's reunification with their Primarch Lion El'Jonson on Caliban, the Lion incorporated the traditions of the Six Hosts with those of his own native knightly brotherhood known as The Order. Thus, the Six Wings of the  Ist Legion were created.The "wings" of the Dark Angels existed beneath the hierarchical structure prescribed by the Principia Belicosa that shaped the other Legiones Astartes, a substrate of organisation and tradition that predated the adoption of the structure of The Order of Caliban and even the amalgamation of the Six Hosts of Angels -- the Hexagrammaton -- but was also a result of both.The  Ist Legion did follow the principles of the later Principia Belicosa, organising their Legion's strength into chapters, led by Masters, and orders, which in turn were led by Paladins. These formations were further broken down into companies, led by captains, and squads commanded by sergeants.Membership in one of the Six Wings of the Hexagrammaton was a mark of skill and worth within the ranks of the Dark Angels. It was a rare sight to note one of their warlords without the insignia of one of these secretive organisations upon their battleplate.Members of the Six Wings were distributed amongst squads and companies, where they acted as captains, sergeants, and line Legionaries, or in specialised formations when assembled on orders from their respective "voted-lieutenant" of a wing. These voted-lieutenants, also called masters, were special officers of the Ist Legion who acted as both commander of their wing and often served as a counsel to their primarch.Voted-lieutenants were elected by their peers rather than being nominated for the rank by a superior officer, hence their name. They would then have their nominated successor chosen to command the wing in the event of their untimely death, so as not to interrupt the cohesiveness of a wing's command structure.The voted-lieutenants who served as the chosen leaders of each wing often gathered together in a group known as the Council of Masters, first in the great fortress of the Ist Legion on Gramarye and later wherever the Legion was engaged after being reunited with their primarch.On the field of battle, a commander responsible for an area of operations or campaign had to request the intervention of one of the Six Wings. When such a request was made and eventually accepted, the members of the requested wing were summoned from their regular duties, when possible, in order to assemble and conduct operations under the command of their voted-lieutenant's orders.The Hexagrammaton formations that existed within the Dark Angels Legion at the time of the Great Crusade and Horus Heresy included the following:DeathwingRavenwingDreadwingFirewingIronwingStormwingThe Deathwing and the Ravenwing are still used by the Dark Angels and their Unforgiven Successor Chapters to this day in their hunt for the Fallen. The other four wings of the Hexagrammaton have been lost to the mists of time and are no longer fielded by the Dark Angels. They have been unseen since the time of the Horus Heresy.