- Trooping the Colour is an annual military parade that marks the Queen's official birthday.
- The ceremony is royal pomp and pageantry at its finest, with military bands, horses, and carriages.
- Thousands of royal fans lined the Mall to watch the parade to mark the Queen's Platinum Jubilee.
The four-day weekend of celebrations for the Queen's Platinum Jubilee kicked off on Thursday with Trooping the Colour, a traditional British royal ceremony and military parade which dates back to 1805.
The ceremony is British pomp and pageantry at its finest, seeing military marching bands, horses, and an RAF fly-past performing around Horse Guard's Parade, the Mall, and Buckingham Palace in central London.
The royal family's senior members, including the Duchess of Cornwall and the Duchess of Cambridge, traveled in traditional carriages, with the Prince of Wales, the Duke of Cambridge, and the Princess Royal riding on horses.
Around 1,400 soldiers, 200 horses, 400 musicians, and 70 aircraft are taking part, the BBC reported.
Trooping the Colour celebrates the Queen's birthday
The Platinum Jubilee is a celebration of the Queen's 70-year reign, but Trooping the Colour traditionally takes place to mark the monarch's official birthday in June every year.
Two previous Trooping the Colour review ceremonies have already taken place in May, one overseen by Major General C J Ghika, and one by the Duke of Cambridge.
The birthday parade on Thursday is the main event, with the Queen and all key members of the royal family in attendance.
Her Majesty, 96, is not taking part — Prince Charles will take her place — but she will be watching from the balcony of Buckingham Palace.
She is expected to be joined by senior members of the royal family including the Duke and Duchess of Cambridge, Prince Charles, and the Duchess of Cornwall.
The Duke and Duchess of Sussex are expected to watch proceedings from a window overlooking Horse Guards Parade, according to the Telegraph.
Thousands of royal fans from around the world lined the streets of the Mall, with some camping overnight to get a good vantage point.
The name Trooping the Colour comes from Army flags
Historically, "colours" was the name for the different flags representing regiments in the British Army, Sky News reported.
To ensure soldiers knew which flag to look out for to find their regiment during battle, officers would march up and down in front of troops with their "colours," known as trooping.
This is where the name Trooping the Colours comes from.