Bolivar Trask designed the original Sentinel robots to police mutantkind in favor of mankind, but they quickly turned against his programming and humanity. These initial models were destroyed following X-Men (1st series) #14-16, but the basic designs have turned up in several black market Sentinel robots across the globe.
The Mark I Sentinel Master Mold contained secret information about The Twelve, thanks to Bolivar's time traveling daughter, Sanctity. This information was passed down, hidden in the programming copied for future Sentinels, as it was also possessed by the Master Mold of Stephen Lang's Mark III Sentinels.
