Wikia

The following events occurred in the 11th century:

Hogwarts School is founded.
Salazar Slytherin creates the Chamber of Secrets and abandons Hogwarts.^{[citation needed]}
Helena Ravenclaw steals her mother's diadem and flees Britain. After hiding the diadem inside of a tree in Albania, she is killed by The Bloody Baron, who then commits suicide. Rowena Ravenclaw passes away not long afterwards.^[1]
A Gaelic poem on Creaothceann is written.^[2]
Gertie Keddle watches and writes about one of the first primitive games of Quidditch.^[3]

Decades

↑ Harry Potter and the Deathly Hallows - Chapter 31 (The Battle of Hogwarts)
↑ Quidditch Through the Ages - Chapter 3 (The Game From Queerditch Marsh)
↑ Quidditch Through the Ages - Chapter 2 (Ancient Broom Games)

Centuries
B.C. era - 1st to 10th century - 11th century - 12th century - 13th century - 14th century
15th century - 16th century - 17th century - 18th century - 19th century - 20th century - 21st century