Fabian was born as a man of common birth in the early 1260s. Despite a lack of formal training, he managed to learn how to properly conduct himself with a lance as well as how to partake in mounted combat thanks to a natural charm that enabled him to befriend several of the local knights in the area. When Edward I declared war on Llywelyn in November of 1276, Fabian saw this as a chance to prove himself and he fought in the battles that would lead to Welsh territories being surrended to the King of England.

Fabian was extremely proud to have assisted in leading his king to victory, and he was granted a title as Viscount of Essex. It was not long this appointment that the vampire Mithras appeared to him. Fabian was extremely receptive to his offer: in exchange for extended life and his loyalty, Fabian was to use his pull within the mortal political system to sway things in favor of outcomes proposed by Mithras. Fabian was happy to accept these terms, and Mithras later offered to extend it to the wife that the viscount took; however, she declined and stated that she would live out only her mortal life with Fabian and their children.

Fabian has remained loyal to Mithras throughout the centuries that have since passed. He has seen Mithras grow distant from his childer, although Fabian noted that Mithras never stopped hoping that his childer would come back to his side. After Mithras began to more frequently leave London during the 19th and 20th centuries, Fabian was left under the charge of his then-seneschal Anne Bowesley instead only seeing his master from time to time.

When Mithras was allegedly driven into torpor by the German Blitz of London during World War II, Fabian assumed him dead and grieved heavily for several decades as he continued to serve under Anne Bowesley in London. He remained in a somewhat disheartened state until one Montgomery Coven approached him in 2000. Fabian was given a position within Syndexioi and immediately went to work furthering his original master's goals.