The Sentinels were first created by Dr. Bolivar Trask, who intended to use them to save humanity from what he saw as a threat to the species' existence in the form of mutants. After, Trask's downfall many Sentinels were created by other organisations and even from the Goverment so as to oppose the mutants.
Omega Sentinel's body , which now is located at Best's lab at Jean Grey School For Higher Learning, aka Karima Shapandar was infected by Sublime's sister, Arkea, who claimed it as her own.
Cyclops and his Uncanny X-men fought the Blockbuster Sentinel at Madripoor which had to the ability to adjust to the attackers attacks after being hit and regenarated every time. Cyclops hinted that it uses high techonology and it would be difficult or a dream to defeat it. At the Sentinel was Disintegrated and returned to its creator.
All New X-menEdit
At the 9th issue of the series the All New X-men learned by Kitty and Jean who read her mind that Sentinels are mutant-hunting artificial intelligence designed to locate and hunt down mutants so as to capture or kill them.
Battle of the AtomEdit
The Sentinels can been at the future fighting the Future X-men. Also, at the present Marvel Universe the All New X-men with professor Kitty located a new mutant who went rogue and her. After that Sentinels, attacked the Original X-men but with the help of the Uncanny X-men they all managed to the destroy the Sentinel but at the last minute the head of one of those Sentinels from before attacked past Cyclops leaving him almost dead but fortunately he was healed by Triage.