Eastern Fringe Campaigns
The Eastern Fringe Campaigns began after the colonists that were part of the Imperium's deepest foray into the unexplored Eastern Fringes were attacked by various Xenos species and were left needing aid. When their plea for assistance was heard, the Imperium sent the Ultramarines and several of their Successor Chapters, to rescue them and the Space Marines had to fight their way through the Hrud, Orks and other Xenos to reach the colonists.[1]
Sources
- 1: Codex: Space Marines (8th Edition), pg. 28 — Chronicles of Ultramar