Dorthan was a male Bolian in the 23rd century. He was one of the first members of the Bolian race to attend and graduate from Starfleet Academy.

He served as a tactical officer aboard the USS Bozeman until 2278, and took part in numerous skirmishes against the Klingon Empire while that vessel was assigned to border patrol. He transferred off the Bozeman only weeks before its mysterious disappearance in the Typhon Expanse.

Lieutenant Commander Dorthan then became tactical officer aboard the USS Gagarin, under Captain Gralev. In 2279, that vessel was attacked and seized by Klingons, and Dorthan was presumably taken prisoner with the rest of the bridge crew. His fate was unknown at the time the imprisonment of eight other Gagarin crewmembers on Pao'la was revealed in 2287. (TOS novel: In the Name of Honor)