The Sleep of the Centuries is a curse used by Maldor that puts people into a sleep that will is almost irreversible. The only cure is the kiss of a Danish Prince.
The 13 Ghosts of Scooby-Doo
Princess Esmeralda fell victim to the curse after refusing to tell Maldor where the Wonder Wand was and placed on a bad and encased in a bed. When Daphne got captured by Maldor, she was also cursed. After Maldor got trapped in the chest, the land was restored to normal but Daphne and Princess Esmeralda will still cursed. They awoke after being kissed (or licked) by Scooby as a Danish Prince.
"Spell of Darkness, trance so deep."
"Now and forever, sleep!"
(Maldor saying the incantation as he puts Daphne to sleep)