The Queen's Diamond Jubilee.
To mark 60 years of The Queen's reign the Diamond Jubilee will take place in 2012.
The celebrations will centre around an extended weekend in 2012 on 2, 3, 4 and 5 June.
The Queen came to the throne on 6 February 1952 and her coronation took place on 2 June 1953. She celebrated her Silver Jubilee (25 years) in 1977 and her Golden Jubilee (50 years) in 2002.
The only other British monarch to celebrate a Diamond Jubilee was Queen Victoria in 1897.