Britain's Queen Elizabeth will spend her birthday doing paperwork. The monarch - who turns 83 Tueday - is planning to spend the day working at Windsor Castle in south west England.

A Buckingham Palace spokesman said Elizabeth has no public engagements or private parties scheduled, and would spend her day going through a large pile of official documents - a task she completes, without fail, every day except Christmas Day.

The representative said: "As always, the Queen will be working."

The King's Troop of the Royal Horse Artillery will fire a royal salute in London's Hyde Park at noon to mark the occasion.

The queen's birthday is celebrated twice a year - once on her actual birthday, and again with an official national celebration in June. This year, her birthday will be publicly acknowledged on June 13 with the tradition Trooping of the Color parade.

British monarchs have been publicly celebrating their birthdays in June since the 1700s because the weather is warmer than other times of the year.