Crowds gathered outside Windsor Castle on Thursday to witness Queen Elizabeth light a beacon to mark her 90th birthday celebrations.

Pageantmaster Bruno Peek (L) hands Britain's Queen Elizabeth II (L) a torch for her to light the first beacon in honour of her 90th birthday in Windsor on April 21, 2016 with Britain's Prince Charles, Prince of Wales (R) following up. The Queen lit the principal beacon which would set in train a series of beacons across the country and worldwide to mark the Queen's 90th birthday.

Prince Charles told the crowd the beacon, one of many set up across the country in the Queen's honour, was a symbol of the support the monarch receives from much of the British public and beyond. The sovereign, on the throne since 1953, emerged from Windsor Castle to accept presents and flowers from hundreds of well-wishers. The beacon was the first of about 1,000 across Britain and worldwide to mark the occasion. There were also artillery gun salutes in London and other British cities.

Born on April 21st, 1926, the Queen has been on the throne for 64 years and is by far the oldest monarch in British history. She overtook her great-great-grandmother Queen Victoria as the longest-reigning sovereign last September.