Events

• William I of England, in a letter, reminds the Bishop of Rome that the King of England owes him no allegiance.
• King Alfonso VI of Castile establishes Roman liturgy in Catholic church in place of Mozarabic rite.
• Ísleifur Gissurarson, the first bishop in Iceland, dies while giving mass in Skálholt church.

Births

• Leopold IV of Austria (d. 1141)
• Teresa of Leon, illegitimate daughter of Alfonso VI of Castile and Leon (d. 1130)

Deaths

• Ísleifur Gissurarson , first bishop in Iceland

• For the snowboard, see 1080º Avalanche.
• For the snowboard, see 1080° Snowboarding.
• For the poison, see 1080 (poison); also known as Compound 1080 or, in the context of pest eradication, simply "ten-eighty".