Stephan became Captain-General quite suddenly in 2963 when his father, Thaddeus Marik, drowned while swimming on Conakry. He inherited a realm that was in a constant stalemate. Every victory on one front was followed by a loss on another.
What followed was a string of setbacks, beginning with the failed conquest of the planet Loric in the Lyran Commonwealth, and then the loss of Wasat to the Capellan Confederation and later Callison to the Lyrans. Mired in a deep political conflict with Parliament, there are indications Stephan actively undermined the defense of worlds under attack as a form of retribution to Parliament's undermining his failed military efforts. By 2990, however, matters were becoming critical, and he was forced to accept Parliament restrictions in return for the continued use of regional troops. By then, however, he was personally weakened.
Setbacks and Death
With acrimonious tensions between Stephan and Parilament freezing funding to both the FWLM and SAFE for many years, following the LCAF's highly successful Deep Raid of 2987 a desperate Stephan recognised that to receive the funding vital to strike back that he would finally have to swallow his pride and accept further concessions and limitations upon the post of Captain-General. After Stephan agreed to Special Resolution 512, giving the provinces a share of spoils of captured territories, and Special Resolution 523, giving Parliament greater say in military dispositions, Parliament quickly loosened the purse strings. 
In 2988, a plot was revealed against the Captain-General, that had sought to replace the current system of Parliament with a military junta, with Stephan's son and heir, Janos Marik as the new Captain-General. Janos, however, refused to cooperate and revealed the conspiracy. SAFE failed to track them down, however. Nevertheless, these and other signs of popular unrest took their toll on Stephan, and he withdrew from public life, finally dying of cancer in August 2991.
Marriage and Children
Stephan had at least one child, Janos Marik, who followed him as Captain-General.
|Captain-General of the Free Worlds League
| Succeeded by|
- Handbook: House Marik, p. 92, "Captains-General in History"
- House Marik (The Free Worlds League), p. 43
- House Marik (The Free Worlds League), p. ??
- Handbook: House Marik, p. 44 "Third Succession War"
- House Marik (The Free Worlds League), pp. 46-47 "Concession to Parliament"
- House Marik Sourcebook|House Marik (sourcebook), p. 44