Soldiers from The King's Troop Royal Horse Artillery mark the eighty ninth birthday of Britain's Queen Elizabeth with a forty one round Royal Salute in Hyde Park, London, April 21, 2015. [Photo/Agencies]

LONDON - Britain celebrated Queen Elizabeth II's 89th birthday on Tuesday.

Elizabeth II, born on April 21, 1926, became Queen in 1952 when her father, King George VI, died.

The queen celebrates two birthdays each year: her actual birthday on April 21 and her official birthday on a Saturday in June, according to Buckingham Palace.

The Queen usually spends her actual birthday in private, but the occasion is marked publicly by gun salutes in central London at midday.

Elizabeth II celebrated her 89th birthday privately at Windsor Castle this year. The King's Troop Royal Horse Artillery employed using six 13-pounder field guns and staged a 41-gun royal salute in Hyde Park in her honor.

The Honorable Artillery Company also fired a 62-gun royal salute near the Tower of London.

Official celebrations to mark British sovereigns' birthdays have often been held on a day in summer other than their actual birthday, increasing the likelihood of sunny weather for the royal birthday parade, officially known as Trooping the Color.

The Queen's actual birthday came at a time when Catherine, wife of the monarch's grandson Prince William, will soon give birth to the royal family's newest member.