Eminem left some fans astounded after they discovered the true meaning behind his stage name.

The American rapper and music producer is celebrated for bringing hip hop to Middle America and breaking racial barriers for white rappers.

His chart-topping hits on the US Billboard Hot 100 include The Real Slim Shady, Lose Yourself, Without Me, Love the Way You Lie, Not Afraid, The Monster, Godzilla and, most recently, Houdini.

The 51-year-old achieved mainstream success in 1999 with his major-label debut album The Slim Shady LP. Since then, he’s been known globally as Eminem, born Marshall Mathers.

However, fans have begun to question the origin of his stage name, with one Reddit user asking: “Why did he call himself Eminem?”

They added: “Does anyone know why he called himself that? I have been listening to him for quite a long time but I never understood why he chose Eminem instead of something like Slim Shady.”

It appears his rap name Eminem dates back to his childhood when he and his high school friend, Mike Ruby, adopted the names Manix and M&M. The name M&M, short for Marshall Mathers, later evolved into Eminem.

Reacting to this revelation, some users expressed their surprise at not having made the connection sooner. One user noted: “He actually used to label his material M&M but he changed it when it started to takes himself more seriously and garner attention to avoid an obvious lawsuit.”