The day kicked off in London's St James's Park, with the Queen's birthday parade and the horse guards parade (the royal horse artillery).
Astute fans will note Prince Andrew (the Duke of York), HRH Prince Charles (the Prince of Wales) and Princess Anne all join in royal salute for the birthday celebration, by doing a march past crowds through to the palace.
But fans all hold out to see members of the royal family all join the Queen to watch the flypast by the royal air force.
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The stunning pageantry - which is broadcast live across the globe - always gets her Majesty to crack a smile.
This year, Prince George and Princess Charlotte had their little brother one-year-old Prince Louis join them for the first time on the balcony of Buckingham Palace to view the colour parade.
One of the best things about the day are the stunning outfits. The royal dress code means their finest threads and definitely no denim jeans.