Prime Sentinels were a team that made their first appearance in X-Factor #123
The Prime Sentinels were the creation of Bastion after he gained the necessary approval from the government to head a Mutant hunting task force code named Operation: Zero Tolerance. With significant resources at his disposal, he was involved in the development of a new series of Sentinels which had been effective mutant hunters in the past. However, unlike its predecessors, these new models were designed to be cyborgs rather than be completely mechanical beings. This allowed the transformed being to retain their innate mental abilities as well as human identity which came along with cunning and creativity but combined it with advanced weaponry to combat the powers of a variety of mutant foes.
Many of the recruits that became Prime Sentinels were volunteers with much of their ranks coming from the Friends of Humanity as well as other individuals that held a strong hatred of mutants. Despite the acquisition of these volunteers, their numbers did not reach a full sized army which was needed in a war against mutants. Thus, Bastion used Operation: Zero Tolerances funds to create new secret facilities around the planet which began converting ordinary civilians into Prime Sentinels against their will. The process also partly involved a technique that replaced the human persona with a more obediant Sentinel mind. Operation: Zero Tolerance began these illegal operations in overpopulated regions such as Calcutta, India, New Mexico and Monkey River Town in Belize where few would notice the disappearances. By offering cures to handicapped people, new Prime Sentinels were formed by willing participants who, unknown to them, were turned into sleeper agents that continued their normal lives until they recieved the activation signal. Others were attracted by being invited to free trips to tourists resorts which they had won and during the vacation they were transformed into cyborgs.
Operation: Zero Tolerance
Eventually, Bastion send the activation signal which resulted in the Prime Sentinels being involved in lightning attacks against mutants around the world. This culminated in an assault on the Xavier Insitute for Higher Learning where Professor Charles Xavier was captured for his own purposes as various individuals associated with the X-Men. However, both the Prime Sentinels and Operation: Zero Tolerance were shut down by the X-Men with the help of S.H.I.E.L.D. Though the programme had been deactivated, some remained in operation though were directionless without Bastion. However, the mutant Stryfe managed to take control of the Belize facility and used it to create Prime Sentinels that were loyal to him though they were ultimately defeated by an alliance of the X-Men and Lady Deathstrike.