Derjan Sefik (b. ???? - d. ????) was a member of the Star League Defense Force during the latter years of the Star League era. By 2766 Sefik had reached the rank of Major and was a member of the elite SLDF Special Forces, commanding the newly-formed 3378th Special Forces Battalion.
Sefik and the 3378th deployed to the Terran Hegemony world of Caph in early December 2766 for what was planned to be several months of training exercises before deployment into the Periphery as a part of the SLDF response to the Periphery Uprising. Instead, Sefik found himself in the middle of a coup; having furloughed his troops within the planetary capital of New Brunnel for the holidays, Sefik discovered that the 118th Amaris Dragoons were deploying on a "training exercise" on the 26th of December. Sefik decided to use the 118th's deployment as an ad hoc training exercise for the 3378th, with his forces shadowing, observing and planning simulated ambushes on the Republican forces; however, as more and more detail became available on the number of critical posts the Republican forces were occupying Sefik became suspicious and redeployed the 3378th to react in the event of an attack from the Republicans.
It was this redeployment that saw the 3378th foil the Republican attempt to seize the planetary HPG when the Rim Worlds Republic forces launched their part of Operation APOTHEOSIS. A day-long battle within New Brunnel followed, with the 3378th receiving critical assistance from segements of the population such as the police force despite the planetary ruler, Duchess Micha Confalonieri, declaring that the Republicans were liberators and that the Caphian population shouldn't engage in resistance.
- Historical: Liberation of Terra Volume 1, p. 80-82, "The Battle For Caph"