The Dark Angels are considered amongst the most powerful and secretive of the Loyalist Space Marine Chapters. They were the Ist Legion of the original 20 Space Marine Legions to be created during the First Founding of the 30th Millennium.
Though they claim complete allegiance and service to the Emperor of Mankind, their actions and secret goals at times seem at odds with that professed loyalty, as the Dark Angels strive above all other things to atone for an ancient crime of betrayal committed over 10,000 standard years ago against the trust of the Emperor during the time of the Horus Heresy.
The Dark Angels stand first amongst the Space Marine Chapters, as they have done since their very inception as the Ist Legion. They are a proud Chapter, with traditions and rituals that date back to the earliest days of the Imperium of Man.