The Crimson Scars were a group of vampiric assassins who split off from the Dark Brotherhood during the year 3E 421.[1][2] Their name derived from the unusually vicious neck lacerations left by these assassins and their jagged blades.[3]
They were founded by Dark Brotherhood member Greywyn Blenwyth, who, after receiving a "vision" from Sithis, conceived an elaborate coup whereby he would infect the ranks of Dark Brotherhood with Porphyric Hemophilia, eventually creating enough vampires to overthrow the Black Hand. Unfortunately for Blenwyth, one of the Brotherhood members he turned, a Dunmer named Silarian, betrayed the Scars to the Black Hand. The Hand then ordered the second "Purification" in the history of the Dark Brotherhood, which destroyed the Crimson Scars, leaving Greywyn and Rowley Eardwulf as the only survivors.[1]
Greywyn subsequently retreated to Deepscorn Hollow and attempted to restore it to its former glory as a new headquarters for the Crimson Scars. However, he ultimately abandoned this goal after receiving a second vision from Sithis indicating disapproval of Greywyn's vampirism.[1]