Duke and Kentucky have a history that goes back to the Southern Conference. When the SEC started up in 1932, they played less often but still played. Both teams made the Final Four in 1966 but Kentucky beat Duke and got the booby prize of playing Texas Western as the poster child of segregated southern sports (Duke had its first Black player, freshman CB Claiborne, but he was a freshman and ineligible, and was also technically a walk-on).
Then of course the teams played in the 1978 Finals.
But it was Christian Laettner in 1992 who put the rivalry on a different level.