Prince William, Duke of Cambridge, and Catherine, Duchess of Cambridge, pose with their son, Prince George, for an official family portrait at Kensington Palace. Jason Bell - Camera Press/Getty Images hide caption

itoggle caption Jason Bell - Camera Press/Getty Images

In a second "first" photo of Prince George, the family's dogs joined in. Tilly, a retriever, is to the Duchess of Cambridge's right. Lupo, a cocker spaniel, is beside the duke. Michael Middleton /PA Photos /Landov hide caption

itoggle caption Michael Middleton /PA Photos /Landov