The fallout of Primus Myndo Waterly's Operation Scorpion and her subsequent assassination by Precentor Martial Anastasius Focht led to a schism within ComStar forming the Word of Blake faction in the Inner Sphere.
Anastasius Focht and newly-elected Primus Sharilar Mori decided to reform the order and remove of many of its mystical trappings, but there was a group of reactionaries who did not agree with these changes. Sticking to the old ways, they seceded from the secularized order as the radical splinter group Word of Blake in 3052. They were a very diverse group in the beginning, united only through their disapproval of the changes within ComStar. Although they initially lacked a coherent leadership, Thomas Marik was almost certainly among their leaders right from the start.
Early on, the Captain-General of the Free Worlds League (Thomas' double, acting as Thomas) allowed tens of thousands of Word of Blake zealots to settle on the FWL world of Gibson. This was almost certainly the real Thomas Marik's doing. He was named Primus-in-exile by them, which was apparently more a honorary title at the time as the various factions of the Word of Blake could not agree on a real leader. The Word also took over the administration of HPGs from ComStar wherever possible, ensuring them a source of revenue.