Hexagrammaton

The Hexagrammaton, colloquially known as the ' Six Wings ', were the specialised formations that existed outside the regular chain-of-command and organisation of the Dark Angels Legion during the Great Crusade and Horus Heresy eras during the 30th and 31st Millennium. These formations owed their existence both to the old formations of Terra - the amalgamation of the Terran pre-Principia Belicosa approach and organistaion of the proscribed formations of the early Legiones Astartes and the ' brotherhoods ' of the Order from Caliban's knightly orders.

History
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. Following The First's reunification with their Primarch Lion El'Jonson on Caliban, the Lion incorporated the traditions of the Six Hosts and The Order, thus, the Six Wings were created. The 'Wings' of the Dark Angels existed beneath the structure of the Principia Belicosa that shaped the Legiones Astartes, a substrate of organisation and tradition that predated the adoption 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 followed the principles of the Principia Bellicosa, organising their Legion's strength into Chapters, which were led by Masters and Orders, which were led by Paladins. These formations were further broken down into Companies, led by Captains. 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 Lieutenants acted as both commander of their Wing and often acted as counsel to their Primarch. Voted-Lieutenants were elected by their peers rather than being nominated by a superior. 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. 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 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 were the following:
 * Deathwing
 * Dreadwing
 * Firewing
 * Ironwing
 * Stormwing
 * Ravenwing