Blackwood Company
The Blackwood Company are in competition with the Fighters Guild, but are much less scrupulous and will accept any job. As you advance in the Fighters Guild, you will encounter them more and more often. They are based in Leyawiin and their headquarters are directly across from the Fighters Guild Hall. The Blackwood Company members use the intoxicating sap from the Hist Tree to boost their combat prowess. When consumed by a non-Argonian, Hist Sap exhibits hallucinogenic properties which can send the drinker into bloodlust. The Hist Tree that the Blackwood Company uses was smuggled directly from Black Marsh, is located in the basement, and is a well-guarded secret. Gallons of the tree's sap are drained daily to fuel its members. Modryn Oreyn believes the specific tree they obtained may be corrupted as it causes even Argonians to hallucinate.
The company started as a mercenary group of former soldiers sent by the emperor to reclaim territory in Black Marsh. After they failed at their task they came to Leyawiin as a new mercenary group. By undercutting the Fighters Guild and agreeing to accept jobs that the Guild refused, the Blackwood Company has grown to over a hundred members and offers a serious threat the to Guild's existence.
In addition to their base in Leyawiin, the Company maintain a lair inside Glademist Cave.
The Company's second-in-command, Ja'Fazir will explain that "Blackwood" refers in part to Blackwood Forest but that it also carries a reference to the "thoghatt", or "charcoal warriors" of Khajiit tradition.
For more information follow
this link. 
