Catherine Duchess of Cambridge and husband Prince William have officially marked their third wedding anniversary this week. The royal couple tied the knot during the royal wedding on April 29, 2011.

According to Us Weekly, baby Prince George and his parents just returned from their three-week tour of New Zealand and Australia last weekend.

Following their eventful trip it seems the two plan to keep things "low-key" for their anniversary celebrations.

An insider revealed, "They chose to make low-key plans but it will still be a special day for them," adding, "They decided to do something low-key and in private before the tour and have been looking forward to celebrating."

In fact Kate Middleton and Prince William are actually enjoying their downtime in London. A palace source admitted, "As always, summer is a busy time for the couple and this year will be unlike any other. Their schedule will be very busy in June, July and August."

Will, 31, married Kate, 32, at Westminster Abbey during a televised ceremony. Although there has not been an official confirmation as to the exact anniversary presents that the royal pair will exchange, the magazine revealed that the traditional British marker of a third anniversary is a gift made from leather.

Unfortunately Prince William and Kate Middleton will be forced to speed their third wedding anniversary celebration along as the Duke of Cambridge is scheduled to link up with his little brother Prince and leave London.

The two will be headed to the United States to attend the weekend wedding of his close friend, Guy Pelly, in Memphis, Tennessee.