Kate Middleton's 27th birthday: The day Prince William joined the RAF

Kate Middleton's children, Prince George, Princess Charlotte, and Prince Louis, along with her husband, Prince William, always make sure she has an amazing time on her birthday.

Over the years, she has enjoyed some wonderful celebrations, ranging from nights out clubbing with her sister, Pippa, to family gatherings with the Middletons.

However, her 27th birthday is likely one she doesn't recall fondly, as she had to say an emotional farewell to William after he made a decision that left her "crushed." 

The couple had been together for years, having met at St. Andrews when they were 19, but Kate's dream of a royal engagement had yet to come true.

In September 2008, despite numerous rumours that the Duke was about to propose, it was officially announced that he would be joining the RAF, a decision that surprised both his family and his girlfriend.

Having just finished assignments with various sections of the Armed Forces, William had two options: return to the Household Cavalry or leave the forces to start his royal duties. 

For William, choosing an RAF career meant extra time and freedom before fully committing to his royal responsibilities, allowing him an independent life that his grandmother and father never had.

For Kate, however, it felt like a setback, as everyone anticipated that she would marry the prince and begin her royal life.