20 iconic photos of Kate Middleton and Prince William

Today marks Prince William and Kate Middleton's fourth anniversary.

After four years together, the couple have adopted a dog, moved into their own home at Kensington Palace, and have welcomed their first child, Prince George.

Now, they're expecting their second child any day.

Though the couple shine at red carpet galas, fundraisers and tours, some of the best moments between the two are candid shots of them laughing and smiling.

Relive some of the couple's most best moments.