It started with a brawl 112 years ago.
Since then, players have climbed into the stands, fans have attacked cheerleaders, threats have been made, households have been divided, Mountain West Conference titles have been won and -- twice -- a BCS bowl berth has been on the line.
Saturday's "Holy War" between BYU and Utah will mark the first time since 1994 (when No. 21 Utah beat No. 20 BYU 34-31) that both teams come into the game ranked. These teams are 9-9 in the past two decades, and 10 of the past 11 games have been decided by a touchdown or less.
This year's game pits 11-0 Utah against 10-1 BYU for not only a share of the conference title, but also a BCS bowl berth.
If you're a Utah fan, the rivalry began in 1896, and during that game there was a full-scale brawl in the stands. So vicious was the scene that the then-Brigham Young Academy disbanded its football program for the next 26 years, which is why BYU's history of the rivalry begins in 1922.
Regardless of when it started, the off-field incidents have become as much a part of the game as the on-field outcomes.
In 1993, Utah players and fans attempted to tear down BYU's goalposts after Utah won in Provo for the first time in 22 years. BYU players put their helmets back on and defended the goalposts. The incident prompted BYU defensive lineman Lenny Gomes to utter these infamous words:
"All those [Utes] think that's all there is to life, but when I'm making $50,000 to $60,000 a year, they'll be pumping my gas. They're low-class losers."
In 1998, BYU linebacker Derik Stevenson attacked a fan in the crowd who was harassing his father. A year later in Provo, a Cougars fan jumped out of the stands and attacked a male Utah cheerleader who was running around the field with a Utah flag after a Utes touchdown. The cheerleader proceeded to beat the fan until police separated the two.
Even the coaches don't like each other. BYU coach Bronco Mendenhall said he and Utah coach Kyle Whittingham have a working relationship.
"There aren't times when his wife and he and we go out to dinner, or things like that," Mendenhall said. "I would say [our relationship is] cordial and professional and really doesn't go much beyond that."
Graham Watson is an ESPN.com football blogger. She can be reached at firstname.lastname@example.org.