The annual display of British military might serves as a seasonally tweaked birthday celebration for the sitting monarch.

Trooping the Colour in the U.K. is a celebration of the reigning monarch's birthday. It's held every year in June, regardless of when their actual birthday is, and it involves a lot of fanfare with a parade and a dramatic RAF flyover.

After arriving at Buckingham Palace by car, Kate and the children, Prince George, 11, Princess Charlotte and Prince Louis, 7, traveled in a traditional horse-drawn carriage down The Mall. Charlotte sat beside her mother, while her brothers faced backward across from them.