Ceris was a member of a Triannon religious faction that believed the "Chosen Realm" was created by the "Makers" in ten days. His faction waged war with D'Jamat's faction which believe it took only nine days.
After D'Jamat's forces commandeered Enterprise NX-01 in November of 2153, he engaged Ceris's ships. Ceris refused to surrender as D'Jamat demanded even though he offered Ceris to not to harm him or his crew. Ceris said that he knew that D'Jamat considered him and his people heretics, and that he knew that they would be killed. The fighting ceased when the Earth Starfleet crew retook the ship and Captain Jonathan Archer informed Ceris about this. (ENT: "Chosen Realm")
Ceris was played by actor Gregory Wagrowski.
His costume without the vest was later sold off on the It's A Wrap! sale and auction on eBay and was previously worn by Alexander Slanger in the second season episode "The Breach". [1] [2]