Forgeworld miniature depicting the Lord High Commander of the Red Scorpions, Carab Culln.
Chapter background (From Lexicanum, http://wh40k.lexicanum.com/wiki/Red_Scorpions):
The origins of the Red Scorpions Chapter are unknown. No records remain of the chapter's founding or from which Space Marine Legion
was first taken. This secrecy has led to some of the Imperium's hierarchy questioning the loyalty of a chapter that keeps its history secret and holds itself answerable to the Emperor
alone. Despite this, the chapter assists wherever it can, carrying out thousands of relief missions. It is known, however, that the chapter has existed for at least 5,000 years.[1a]