1900-2020
During the Twentieth Century, the wizarding community deals with two major conflicts, each of which is instigated by a Dark Wizard of prodigious power. In each of these conflicts, the risk of exposure to the Muggles is great. And in each case, one person stands in the end against evil and is victorious: Dumbledore over Grindelwald in 1945 and Harry Potter over Voldemort in 1998. After the second of these uprisings, the Ministry of Magic is reorganized and improved as the Twenty-First Century dawns.

The Rise of Grindelwald – 1900 – 1945
Calm between Wars – 1945 – 1960
The Marauders and the Rise of Voldemort – 1960 – 1981
Voldemort in Hiding – 1981 – 1990

The Second Rise and Defeat of Voldemort:

1991-1992 – Harry’s first year (PS)
1992-1993 – Harry’s second year (CS)
1993-1994 – Harry’s third year (PA)
1994-1995 – Harry’s fourth year (GF)
1995-1996 – Harry’s fifth year (OP)
1996-1997 – Harry’s sixth year (HBP)
1997-1998 – Harry’s seventh year (DH)

The Post-War Years
1998-2017
The Next Generation
2017-2025