A diamond jubilee celebrates the 60th anniversary of a significant event related to a person (e.g. accession to the throne or wedding, among others) or the 60th anniversary of an institution's founding. The term is also used for 75th anniversaries, although the human lifespan makes this usage more common for institutions.
George III of the United Kingdom died nine months before his diamond jubilee was due in 1820. The Diamond Jubilee of Queen Victoria celebrated her 60-year reign on 22 June 18...