Hebron came from the planet Paraval, a world which was enslaved by the Goa'uld a generation ago. At an unknown time, he came in contact with the Tok'ra and volunteered to become a host for one of their symbiotes.
After Shan'auc had informed both Stargate Command and the Tok'ra about the wishes of her symbiote to join the Tok'ra, the rebels found a willing host in Hebron. When he was presented to Shan'auc and SG-1, Colonel Jack O'Neill quickly asked Hebron whether he truly wanted to do this. Hebron was positive about this and after talking with Shan'auc about the symbiote, the Jaffa sensed that the Goa'uld reached maturity. After the symbiote left her pouch, Hebron presented himself as its host, with the Goa'uld jumping at him and biting through his neck to take his new host. Shortly thereafter, the Goa'uld presented himself as Tanith. Although he appeared to be like the other Tok'ra, reaching true symbiosis with it host, in truth, Tanith repressed Hebron's mind, a fact he revealed to Shan'auc before killing her. (SG1: "Crossroads")
For the next year, Hebron's body was controlled by Tanith while Hebron's own mind was presumably suppressed as well. Thankfully, Hebron's prolonged suffering came to an end when Tanith was killed by SG-1 member, Teal'c of Chulak in revenge for Tanith murdering Shan'auc. (SG1: "48 Hours")