As they wait for the arrival of their second child, the Duke and Duchess of Cambridge have another milestone to celebrate; their fourth wedding anniversary.

It’s hard to believe that it was four years ago that the royal wedding dominated the media and the bride’s sister, Pippa Middleton, captured the attention of the world.

Hello! Magazine reports the royal couple were seen returning to Buckingham Palace on Wednesday to celebrate their anniversary. Earlier this week, Duchess Kate was seen taking Prince George to his swimming lesson with their nanny, Maria Teresa Turrion Borrallo.

Kate is several days past her due date and it’s believed she might have the baby early next month. Well wishers have been camped outside of the Lindo Wing of St. Mary's Hospital, where she had Prince George and will have the second baby as well.

Kensington Palace posted a video in honor of the Duke and Duchess’ wedding day in 2011 and wrote, “Four years ago today The Duke and Duchess of Cambridge were married at Westminster Abbey.”

video via Twitter from Kensington Palace

image via Camden/INFphoto.com