X-Men (Vol 1 1963) Issues 1-50

The first 50 issues of the X-Men were pioneered by the iconic duo of writer Stan Lee and artist Jack Kirby, who established the foundational elements of the series, introducing the original team of mutants and their mentor, Professor Charles Xavier. This era is notable for setting the stage with its mix of superhero action and social allegory, highlighting themes of prejudice and acceptance. Kirby's dynamic art style gave life to the team's diverse abilities and personalities until issue #20. From there, Roy Thomas took over the writing duties, bringing fresh narrative directions, while artists like Werner Roth, Dan Adkins, Ross Andru, and Don Heck, among others, took on the visual storytelling. These artists continued to develop the series' visual identity. Key issues include; 

#1  - 1st appearances Professor Charles Xavier, Magneto, Cyclops, Beast, Angel, Iceman, Marvel Girl
#2  - 1st appearance The Vanisher                                #3  - 1st appearance The Blob
#4  - 1st appearance of Mastermind, Toad, Quicksilver, Scarlet Witch.
#8  - 1st appearance of Unus                                         #9  - 1st appearnace of Lucifer
#10 - 1st appearance of Ka-Zar, Zabu                           #12 - 1st appearance & Origin of Juggernaut
#16 - 1st full appearance of Master Mold                     #19 - 1st appearance of Mimic
#28 - 1st appearance of Banshee                                  #35 - 1st appearance of Changeling
#44 - First Silver Age appearance of Golden Age Red Raven
#49 - 1st appearance of Polaris