Enacted by the Terran Alliance's Liberal Party in 2242, the Demarcation Declaration granted independence to all worlds beyond a 30 light year sphere around Terra, whether they wanted independence or not. Subsequently left to fend for themselves, the Declaration lead to the consolidation of the colonies and formation what became the six Great Houses.
By the time of the Fourth Alliance Grand Survey, the world of Marik had become an important and closely-allied world of Terra. Though never aligned one way or the other during the Outer Reaches Rebellion, the influence of the Alliance military (via enforced supplying of operations) started to tilt the populace in the direction of the dissidents. In 2237, Senator Charles Marik overtly began supporting the insurrection and publicly declared the planet's independence in 2238. Prior to Terra's formal declaration, the Marik family had already petitioned nearby worlds to join an alliance centered around a collective defense.
- Handbook: House Marik, p. 12, "To The Stars"