X-Men #14

Published in November 1965, X-Men #14 marked a pivotal moment in the Silver Age of comic books as it introduced the Sentinels, a team of giant mutant-hunting robots. Conceived by writer Stan Lee and artist Jack Kirby, this issue was part of a deliberate effort to expand the X-Men's rogues' gallery with threats that challenged the team both physically and ideologically. The design of the Sentinels, with their distinctive purple and red armor and imposing silhouettes, became one of the most enduring visual motifs in the franchise's history.

The story, titled 'Among Us Stalk... The Sentinels!', centers on the scientist Bolivar Trask, who constructs these machines to protect humanity from the perceived threat of mutants. This narrative choice added a layer of sociopolitical commentary to the series, framing mutant prejudice as a central pillar of the X-Men mythos. Upon its release, the issue was well-received for its action-oriented pacing and for establishing a recurring, high-stakes antagonist that would define the X-Men’s struggle against systemic intolerance for decades to come.