Who is Marvel Comics’ first mutant? X-Men history explained

Marvel Comics has a lot of X-Men, and the very first mutant has a unique connection to the popular mutant superhero team. 

The X-Men have a long and storied history, first debuting all the way back in 1963’s Uncanny X-Men #1. 

Since that debut, the X-Men have made a name for themselves with a massive roster of mutants that spans generations. 

Many mutants have since been cited as the first mutant, but Marvel’s revelation of the oldest known mutant is actually a fairly recent affair. 

Marvel Comics’ first mutant is Lady Phoenix

Currently, the first known mutant in the Marvel Universe is Firehair, also known as Lady Phoenix, of the Prehistoric Avengers. A number of characters have been teased and speculated as having come first, including Apocalypse, Mr. Sinister, and even Wolverine, but Lady Phoenix predates them all by centuries.

Introduced in 2017, Lady Phoenix is also the earliest known host to the cosmic entity known as Phoenix. We see her alongside prehistoric counterparts to the modern Avengers, including an early Iron Fist, the Starbrand. 

Lady Phoenix also fought alongside Odin, whom she took as a lover. That tryst was briefly rumored to have resulted in Thor but was quickly disproven when Gaea, the goddess of Earth, revealed herself to be Thor’s mother. 

Why does Marvel call Namor the first mutant?

Namor is not the first mutant in the Marvel universe, but he is the first canonical one. He first appeared in 1939’s Marvel Comics #1, where he’s actually a villain. These events are later written out in canon with Namor having been mind-controlled. 

Namor is far from being the first mutant, though, with plenty of others predating his birth in the 1920s. In reality, the typical The First Mutant slogan given to Namor is just for marketing, referring to him being the first mutant published by Marvel. 

Most of Namor’s powers, including his strength, ability to breathe in and control water, and his rapport with sea creatures, are attributed to his human-Atlantean physiology. The exception is his power of flight, which is believed to be a mutant power.