1170s

The 1170s was a decade that started on 1 January 1170 and ended on 31 December 1179. It is distinct from the decade known as the 118th decade which began on January 1, 1171 and ended on December 31, 1180.

• 1170 – Assassination of Thomas à Becket
• 1171 – Saladin ends the Islamic ruling of Fatimid, bringing back Sunni rule in Egypt.
• 1179 – Third Council of the Lateran condemns Waldensians and Cathars as heretics (people who turn away from certain religious beliefs); reformation of clerical life