Sentinels

Sentinels are the name attributed to various models of robot featured in comic books published by Marvel Comics. They are part of the mainstream Marvel Universe, colloquially referred to as the Earth-616 reality, but have also been represented in stories that take place in alternate realities as well. They are traditionally associated with stories dealing with the X-Men.

The original Sentinels, the MK I model, were first introduced in the pages of X-Men, Volume 1 #14 in November, 1965 in a story called "Among Us Stalk... the Sentinels!". The more popularly known models are the MK III models, which were first introduced in X-Men, Volume 1 #98 in the story, "Merry Christmas, X-Men — The Sentinels Have Returned!" in April, 1976. There have been many different models of Sentinel since then, varying in appearance, design, capabilities and programming.