When did Queen Elizabeth celebrate her Golden Jubilee, i.e. 50 years on the throne?

Explanation

Elizabeth II (Elizabeth Alexandra Mary, born 21 April 1926) is the constitutional monarch of sixteen independent sovereign states known as the Commonwealth realms. She is the second-longest reigning monarch in the world, and has been on the throne since 6 February 1952. She could thus celebrate her Golden Jubilee in 2002.