Brock Lesnar vs. Undertaker: A Brief History of WWE's Sum

This Sunday, the two biggest attractions WWE has to offer will collide in the main event of SummerSlam. It's a monumental match—and one with years of history behind it.

WWE television is quick to reference WrestleMania 30 as the genesis of this bout, but this feud has been raging for more than a decade. The Phenom has been at war with The Beast for a very long time indeed.

At this point, the pair can safely count themselves among one another's greatest opponents. Few men have taken the fight to The Undertaker as Brock Lesnar has, and the same could be said with the roles reversed.

Sunday could be the conclusion of this mythic rivalry. Before we see the end, here's a recap of the journey that delivered both men to the main event of SummerSlam 2015.