Rak'nor's father, the Jaffa Delnor, burned the Goa'uld symbol off Rak'nor's forehead in the belief that all Jaffa would soon be free -- a belief inspired by Teal'c's rebellion against the false gods. Unfortunately, Rak'nor watched his father die because of what he did, and came to see his beliefs as blasphemy against the gods. He fell into the service of the powerful Heru'ur.
Rak'nor captured Teal'c by pretending to be sympathetic to his cause, and handed him over to the Goa'uld. He was present for much of Teal'c's torture at the hands of Terok, but decided to betray his master to free Teal'c when he convinced him of his cause. Both Rak'nor and Teal'c escaped in a death glider moments before Heru'ur's Ha'tak was destroyed by Apophis.
Rak'nor joined the rebel Jaffa, and maintaining faith in the goal that all Jaffa would one day be free, helped to lead the rebels on Teal'c's behalf.
The Serpent's Venom - Rak'nor captures Teal'c and delivers him to Heru'ur for torture. But Teal'c convinces him that the Goa'uld are not gods, and Rak'nor helps him escape.
The Warrior - Teal'c finds that Rak'nor has joined the ranks of a rebel Jaffa group under the charismatic Kytano -- who turns out to be a power-hungry Goa'uld.
Allegiance - A hot-headed Rak'nor makes SG-1's job keeping the peace more difficult when the rebel Jaffa clash with Tok'ra refugees at the S.G.C.'s Alpha Site.
Orpheus - Rak'nor joins Teal'c and SG-1 on a mission to a Goa'uld death camp, where they must risk their lives to free Master Bra'tac and Teal'c's son.