Doran Sarkin-Tainer, named after his father's original family name, was the offspring of Tyria Sarkin, a Jedi Knight, and Kell Tainer, a pilot from Wraith Squadron. Possessing a handsome, square-jawed appearance, he was described as being "the size of a dwarf Wookiee."
Tyria journeyed across the galaxy with her son, Doran, instructing him in the ways of the Force both before and during the Yuuzhan Vong War, while Kell, her husband, was engaged with the Wraiths. At the conclusion of the Yuuzhan Vong War, Doran and his parents united with other Jedi on Zonama Sekot.
Doran participated in the Second Galactic Civil War as one of the Jedi Knights involved in Operation Roundabout, the attempted kidnapping of Thrackan Sal-Solo from his Corellia estate, working as part of Team Tauntaun with Tahiri Veila and Tiu Zax. They gained access to the mansion by posing as utility workers, only to discover that it was a setup, heavily guarded by dozens of guards, combat probots, and YVH 1 droids protecting the room where Sal-Solo was expected to be. Veila gave the order to retreat, but Doran suggested disguising a Protocol droid as a deceased Jedi, allowing one of them to stay behind and gather intelligence. Zax noted that Doran was too large for the role and volunteered himself. After the droid was prepared, Doran and Veila carried it out of Sal-Solo's mansion, commandeered a groundspeeder, and made their way to Behareh Spaceport to rendezvous with Team Purella.
Upon their arrival, Doran assured Jaina Solo that the "body" in the back wasn't what it seemed and explained the situation, deducing that they too had been ambushed based on the injuries sustained by several other Jedi. Jaina, though displeased about leaving a team member behind, acknowledged the value of obtaining information from Sal-Solo's residence. She instructed Doran to acquire Bacta patches for Zekk's burns and something to aid Kolir Hu'lya's injured mouth, while Thann Mithric secured a getaway vehicle. Mithric obtained a shuttle, and Doran, along with the other Jedi, escaped the planet under the escort of Hardpoint Squadron.
In 43 ABY, Doran was among the Jedi called upon to manage the media and Galactic Alliance Security during the apprehension of Valin Horn. He arrived alongside Jedi Master Kyp Durron to assist in securing the psychotic Jedi. In 44 ABY, Doran took part in the raid on Detention Center 81, the rescue attempt to free Valin and Jysella Horn. Along with Bandy Geffer, a Jedi Apprentice, he piloted an airspeeder disguised as a HoloNet News vehicle, helping to extract "Team Saav'etu", "Team Solo", and the Horn siblings.
Being a Jedi, Doran possessed the ability to manipulate the Force.