On this day, December 9, in 2001, the WWE hosted Vengeance, their final pay per view of the year, and made history in the process.
After vanquishing the Alliance once and for all at Survivor Series, the company was left with two top titles, with The Rock reigning as the World Champion (formerly the WCW World Championship), and Stone Cold Steve Austin holding the WWF Championship.
To have one Superstar as top dog, the WWF co-owners made a 4-man tournament, with Austin defending the WWF Title against Kurt Angle, The Rock defending the World Title against Y2J, with the winners facing to crown the Undisputed WWF World Champion.
After defeating The Rock, Jericho was instantly put against Austin, who had retained his title earlier that night against the Olympian.
Despite no rest-time (and already tapping out, though the referee was incapacitated), Jericho was able to pin Austin, with some help from Booker T, to become the first WWF Undisputed Champion.
Whilst his reign may have left a lot to be desired, as he was the third person in the Triple H-Stephanie McMahon feud of 2002, no-one can take this historic accolade from the Ayatollah of Rock and Rollah.