Rojan's ancestors originally began the voyage in multi-generational spacecraft centuries before, and by the time the ship reached the galactic barrier in the mid-2260s, Rojan had become leader of the group. Unfortunately, the Kelvan spacecraft was destroyed during the passage through the barrier; Rojan and four others were able to escape to a nearby Class M planet. In order to adapt to the environment around them, Rojan and the others established a humanoid form.
In 2267, the Kelvans sent out a false distress call which quickly drew the attention of the USS Enterprise. When Captain James T. Kirk led a landing party to the surface, Rojan and the others quickly overpowered them and, upon beaming up to the Enterprise, seized control of the vessel. After outfitting the Enterprise with advanced Kelvan propulsion technology, Rojan took the Enterprise out beyond the barrier and headed back to the Andromeda Galaxy. In order to assure the cooperation of Captain Kirk and three other senior officers, Rojan turned the rest of the crew into cube-shaped objects which could easily be stored.
Fortunately, the Enterprise crew were able to regain the ship when Captain Kirk and the others began to draw Human emotions out of the Kelvans. Kirk was able to make Rojan extremely jealous by seducing Kelinda, a fellow Kelvan. Rojan finally accepted that his emotions could be fully realised in the Milky Way Galaxy and that he could never return to his original Kelvan form; the Kelvans then returned control of the ship to Kirk. (TOS episode: "By Any Other Name")
Rojan and the President of the United Federation of Planets established a peace treaty between the Federation and the Kelvan Empire. Rojan became a leader of a Kelvan colony close to the galactic barrier and dispatched robot probes to Andromeda reporting on their situation, and the offer of assistance that the Federation had made. (TOS - Strange New Worlds 9 short story: "Gone Native")
In the late 26th century, Rojan - along with his fellow Kelvans - had long since settled into a peaceful life as a farmer. Rojan met with Prefect Tamar, who had been dispatched by the Kelvan High Command to punish Rojan for abandoning his mission of conquest. Rojan argued that the Empire should join the Federation, but Tamar refused to listen to anything Rojan said. Rojan then had Drea launch the formal, signed Federation/Kelvan peace treaty to Andromeda, telling Tamar that it was a galaxy bomb. He then had Kelinda turn Tamar into a cube. (TOS - Strange New Worlds 9 short story: "Gone Native")