Commander has been around quite a long time now. Originally a casual format that Sheldon Menery shared with his Judge peers and friends when off the clock at Pro Tours and Grand Prix tournaments, he began sharing it with the wider Magic audience around 2004 (Elder Dragon Highlander Update).
Sixteen years later, it's fair to say that Commander is the most popular format in the game. That's some serious growth in fandom!
As a non-Judge, I came to the format later than some, but I've been playing multiplayer Magic since I bought my first Starter deck in 1994, so reading about the format from Sheldon certainly piqued my interest. In 2007 my local playgroup had lost interest in casual multiplayer and I was looking for a way to put a fresh spin on it. After talking with Sheldon at a Star City Games event earlier that year, I was eager to give it a try. It immediately caught fire with my local playgroup, and soon after I began writing about the format semi-regularly before eventually focusing exclusively . . .