He formed a committee to find alternative solutions, the least of which was to remove the Dementors, which met opposition from those who feared a mainland invasion by the dark creatures if they were deprived of their food source.
When Damocles Rowle was elected Minister for Magic in 1718, he insisted on utilising Azkaban's dark pedigree, seeing the Dementors as a potential asset: putting them to work as guards would save expense, time, and lives.This plan was eventually put into motion and, despite protests, Azkaban remained the prison of the wizarding world right up until the Second Wizarding War, mostly because of its near-zero breakout rate.Harry endured a second encounter with a group of Dementors during a Quidditch match, causing him to lose consciousness and suffer a fall from his broom.He was that time rescued by Dumbledore, who slowed Harry's fall and then drove the Dementors away with a Patronus.Perhaps its first resident, or even creator, Ekrizdis, practised the worst kinds of Dark magic and constructed a fortress on the island, luring Muggle sailors there to torture and murder them.
After his death, the various concealment charms placed on the island faded, and the Ministry became aware of the mysterious site's existence.
Whenever brought into close proximity with one, Harry was forced to relive his worst memory: hearing the last moments of his parents' lives before they were murdered by Lord Voldemort.
The first of these encounters was on the Hogwarts Express, during which he was protected by the new Defence Against the Dark Arts professor, Remus Lupin.
During the 1993-1994 school year, Dementors were sent to guard Hogwarts School of Witchcraft and Wizardry against "mass murderer" Sirius Black, who had recently escaped from Azkaban in 1993.
On the Hogwarts Express, Harry Potter had his first encounter with a Dementor.
Get too near a Dementor and every good feeling, every happy memory will be sucked out of you.