From Warhammer 40k - Lexicanum
Nemedeus was a Captain in the Blood Angels Legion during the Great Crusade who fought beside the Primarch Vulkan and the Salamanders Legion in the Artagean campaign.
The Captain and his entire Company were later killed while fighting in the Ullanor Crusade. Their deaths were recorded in the Blood Angels' history as being one of its greatest sacrifices. His personal power sword was recovered by his Legion after his death and was later wielded by Captain Valefor when the Ork forces of The Beast invaded the Imperium.
- 1: The Beast Must Die (Novel), Chapter 20