1940s

The following events occurred in the 1940s:

Events

1940: Rubeus Hagrid starts at Hogwarts.
1940 to 1945: Grindelwald's Revolution.
1942: Tom Riddle opens the Chamber of Secrets. Several students get injured, Moaning Myrtle gets killed by the Basilisk. Hagrid is framed for the attacks by Riddle and is expelled.
1943: Tom Riddle murders his father, Tom Riddle Sr. and his grandparents, for his abandoning of his late mother, Merope Gaunt. His uncle, Morfin Gaunt was framed for the attacks by Riddle and is sent to Azkaban.
1944: Minerva McGonagall graduates from Hogwarts School of Witchcraft and Wizardry.
1945: Tom Riddle graduates from Hogwarts School of Witchcraft and Wizardry.
1945: Albus Dumbledore defeats Gellert Grindelwald, who is sentenced to life in Nurmengard.
1946: Tom Riddle murders Hepzibah Smith, stealing artifacts of Helga Hufflepuff and Salazar Slytherin
1947: The Werewolf Register is introduced.
1947: A History of Magic by Bathilda Bagshot is first published.
1949: A hippocampus is caught by Merpeople off the coast of Scotland.

According to the mini-adventure The Queen's Handbag, Augusta Longbottom, grandmother of Neville Longbottom, was the victim of a prank by her husband involving her handbag and a fanged gerbil in 1947, leading her to booby-trap her handbags from then on (leading to some pain for Ron Weasley). The Queen's Handbag breaks from canon in several places (not least of which by being set in 2006), so therefore whether anything included in the adventure actually counts as continuity is a matter of debate. This piece of information regarding Longbottom is listed here, however, as the only piece of new Potter Universe backstory offered in the mini-adventure.