Hulk Hogan's reign atop the wrestling world lasted 1,474 days from January 1984 until February 1988. That's a little over four years as the WCW World Heavyweight Champion. If you only consider WWE's recognized number of days, which is 1,177, this still more than twice the second- and third-longest championship reigns that's recognized by the WWE, which is held by Ric Flair at 501 and 505 days, respectively.
While the verdict is still out on whether the WWE will eventually recognize Roman Reigns' stay as the Undisputed WWE Universal Champion, which currently stands at a little over 740 days (and counting), it's safe to say that the Tribal Chief still has a lot of catching up to do to Hogan.
If we believe the recent reports, Reigns could come closest to any wrestler. Reigns will hold on to the unified title belt for at least the end of the year.