Ten milennia ago, the Emperor formed the legions of Astartes that would conquer the galaxy in his name. The first and greatest of these was known as the Dark Angels. After the dark days of the heresy had subsided, the Imperium found the Dark Angels in seclusion, with newly-coloured armour, and demanding autonomy according to their charters. Granted such, the 'new' Dark Angels began a mission that the rest of the Imperium must NEVER know about.
The first company is made up entirely of veteran battle brothers, all versed in the art of war and true history of the legion completely. Their knowledge is both valuable and dangerous, being the strength and spine of the entire Dark Angel's chapter. The battle brothers are all trained in the use of the Tactical Dreadnought armor, known more commonly as 'Terminator Armor'. Their standard tactic is the deep strike, teleporting directly into the enemy's ranks where they can wreak untold havoc and massive destruction. Their faith is unquestionable, they are fearless, and they are the Deathwing.