It was first worn by England's Edward the Confessor in the 11th century—mostly on holidays. It became a holy relic when he was canonized in 1161.
St. Edward's Crown, as it came to be called, was meant to adorn subsequent royalty on their coronations, and was used for that purpose from the 13th to the 17th century.
After Parliament abolished the monarchy in 1649 during the English Civil War, it was melted down altogether.
A restored version of the crown, made for Charles II in 1661, is the one that was worn in 1911 by George V, in 1937 by George VI and during the last coronation, of his daughter, nearly 65 years ago.