By most measures, 2011 is the Year of the Sequel; there are more follow-ups coming out this year than ever before, which is really saying something. (Remember 2009, when we got new Transformers, Terminator, and Twilight movies and a Squeakquel? That was a mere runner-up!) And on June 3, we’ll see that increasingly common subspecies of sequel: the prequel, this time in the form of X-Men: First Class. Once a rare phenomenon reserved either for inordinately ambitious storytellers or moguls out to make a desperately quick buck (and, maybe in the case of one George Walton Lucas Jr., both), it’s quickly becoming a popular approach for any big Hollywood franchise wishing to either reinvent itself or reboot with cheaper actors. So just as prequels tout themselves with the come-on “See how [iconic villain/hero] became the character we all know,” let’s take a history course and see just how prequels became the trend we all know.