The White Rook Division of Castle Pharmaceuticals, they are the secret branch of Castle Pharmaceuticals that handles B.O.W.s (Bio-Organic Weapons). They specialize in the research of the Z-Virus (and to a limited extent the lesser X-Virus) and finding a way to make it a viable weapon.
While Castle Pharmaceuticals was founded in 1862 by Dr. Ian Castle and Dr. Ryan Maxwell, the White Rook Division didn't come into existence for another 63 years. White Rook was founded after Dr. Elizabeth Smitherson discovered the Pedes Mortis Virus (called the X-Virus initially), when she was only 25 years of age in 1925. While publicly calling for the eradication of the Pedes Mortis Virus, Castle Pharmaceuticals founded the White Rook Division to study and look for ways to use the virus as a weapon.
Dr. Smitherson was chosen to be the first Director of White Rook. It was under her that White Rooks current structure was formed. Due to her interest in the game of chess, Dr. Smitherson named the new division White Rook, and instituted chess related titles for all White Rook Staff. Dr. Smitherson became the very first Black King, a title still used by the head of the White Rook Division.
In 1943 Dr. Smitherson and her team discovered the Z-Virus, a more virulent version of the Pedes Mortis Virus, which reaminmated the host for a longer period of time and halted most decaying of the hosts body. Unfortunately Dr. Smitherson was infected by one of her test subjects in December of 1945 along with 80% of the staff at the facility, when the subject got loose. It is rumored that the subject was intentionally released by a rival looking to take over White Rook from Dr. Smitherson. A US National Guard unit was called in to eradicate the infected, and unfortunately all but one Guardsman were killed when the facility went up in flames. The survivor was Capt. James Keller.
In January of 1946 Capt. Keller was recruited by White Rook to establish an in house security force. This force in addition to providing security to all Castle Pharmaceutical facilities (both legit and subversive) acts as a clean up crew for any "accidents" that may happen. Capt. Keller named the new security force the Black Knights, keeping with Smithersons chess theme. Ultimately the Black Knights fall under the umbrella of White Rook due to the true nature of their existence, though they are also the only know part of White Rook that is publicly known. Their public image is that of Castle Pharmaceuticals armed security force for their facilities and upper echelon.
All White Rook facilities operate under the cover of another legitimate Castle Pharmaceuticals facility. Most of the White Rook facilities are actually housed underneath the legitimate Castle Pharmaceutical facility and accessed via a secret entrance. In addition most White Rook facilities consist of one main complex and a number of smaller satellite complexes that may be as far as 10 miles away, these smaller complexes are connected tot he main complex via an underground tram system. Each facility is color coded based on the Bishop (the head of the facility) in charge, so a facility run by the Red Bishop would be coded Red, along with any staff (pawns) stationed there, excluding Black Knight personnel. Using the color coding example above if the Red Bishop was assigned to the Omicron Facility, it would then become the Red Omicron facility and the satellite complexes would be referred to as Red Omicron 2, Red Omicron 3, etc... and all personnel would be referred to as Red Pawn Smith (if the personnel member's last name was Smith), if more then one member of the facilities personnel share the same last name the initials for their first and middle names are used, ie Red Pawn J. M. Smith and Red Pawn S. B. Smith.
The current number of facilities and total number of personnel are only known to the Black King and a select few within White Rooks and Castle Pharmaceuticals ranks.