When Moloc decreed that only male Jaffa would survive, having begun to believe that the female Jaffa were weaklings, Ishta, one of Moloc's high priestesses organized an underground movement to spirit infant girls to Hak'tyl.
After learning of SG-1, they approached the Tau'ri, seeking an alliance. Major Samantha Carter, the only female member of SG-1 later approached them and offered them Tretonin as a way of being free of the Goa'uld symbiotes so that the group itself would not have to resort to raids in order to steal symbiotes for their younger female followers. Though it was difficult at first, the Hak'tyl were convinced to take the tretonin. (SG1: "Birthright")
During the conquests of Ba'al, the Hak'tyl organized a group of at least 2,000 Jaffa, both male and female,to rebel against Moloc. Teal'c and Bra'tac urged caution, saying that killing Moloc would ultimately do nothing in the long run as another System Lord would likely take his domain.
However, a rebel meeting was interrupted by Moloc's forces on the new Hak'tyl homeworld, leading to Moloc himself coming to torture Ishta. Teal'c rescued Ishta from Moloc's First Prime Cha'ra (who later joined the Jaffa Rebellion) while rebel Jaffa Aron directed a missile strike from the SGC onto Moloc, killing him and destroying his forces on the planet. Unfortunately, in spite of the victory and as Teal'c and Bra'tac had predicted, with Moloc dead, Ba'al absorbed his domain and became more powerful than ever before. (SG1: "Sacrifices")
With the collapse of the Goa'uld Empire and the emergence of the Free Jaffa Nation, the Hak'tyl have emerged as a force in the politics of the Jaffa High Council and were accorded a seat in the council, taken by Ka'lel, due to their military strength. They usually ally with the progressives such Teal'c and Bra'tac in the support of establishing a democracy (despite the fact it could weaken their political powers) against the Traditionalists lead by Gerak, and have also opposed the Ori. (SG1: "The Fourth Horseman, Part 2", "Stronghold")