Dimsdale was appointed the tax collector of De Vil Ville over 300 years before the series. Because he was so ruthless, he soon gained more titles, including sheriff, notary public, judge, bail bondsman, birthday clown, dog catcher, comedy driving, school, and Lord Mayor. Like a true De Vil, he ran the town with an iron fist, and (literally) squeezed every bit of money out of the locals. Some time after (exactly three-hundred years before the episode took place), Hester Hen, the town witch, showed up and, realizing that the judge will not rest until he owns the whole world, casts a spell over Dimsdale and the whole town, so that it would disappear from the earth, to return for one day every 100 years, to keep the world safe from De Vil's evil. The curse also bound De Vil to the town, on risk of death, and made the townspeople bewitched and mindlessly happy, to make him all the more miserable in comparison. The only exception to this spell were chickens (which is to avoid cursing Hester Hen's: Katrina).
The third day after Hester Hen's curse was cast (i.e. 300 years later), Roger and Anita Dearly, along with Lucky, Rolly, Cadpig and Spot, wandered into De Vil Ville. All except Spot fell under Hester's curse. Cruella De Vil, Dimsdale's great-great-great-great-great-great-granddaughter, found her way into De Vil Ville as well. She persuaded Dimsdale to lock the Dearlys in the town jail, so that when she returned to Grutely, they'd disappear for the next 100 years, so she could claim their farm. Dimsdale, however, as he realized that, when Hester had cursed the town, she had just said "The evil De Vil will be bound within the town's borders" and hadn't specified which evil De Vil. Seeing that Cruella was just as evil as he was, he locked her in stocks and made to leave the town.
While he was collecting his gold, Spot kissed the puppies and the Dearlys, breaking the curse, and, in turn, allowing Anita to free Cruella. Cruella tackled Dimsdale as he headed for the town's exit, and they fought. When Cruella saw the sun setting, she ran for the exit, but Dimsdale grabbed her legs and pulled her back. Roger and Anita tried to pull Cruella free, but all three started to get pulled back in. Remembering that chickens were invulnerable to Hester's curse, Spot flew at Dimsdale, and caused him to let go of Cruellla. When the village vanished, Spot was left behind, as she protected, and Dimsdale was still trapped within the town.