While Kate wowed the crowd in a stunning Alexander McQueen white gown, Queen Elizabeth II wore something even more breathtaking, the Burmese Ruby Tiara.
The special headpiece has a rich history, with the Queen first commissioning the ruby and diamond tiara in 1973 from London based jewellery company, The House of Garrard.
The tiara is said to have been made entirely by hand and has 96 rubies (the gems were a wedding gift from the people of Burma) encrusted upon it.
The breathtaking tiara also has diamonds from the Nizam of Hyderabad.
But why is this tiara so special?
According to Burmese tradition, rubies are said to protect their owner (or in this case wearer) from evil and illness.
Whether the tiara succeeds in repelling any malevolence remains to be seen, but it certainly is pretty!