It's the most wonderful time of the year! The royals are spending Christmas day at the Queen's Sandringham estate for an annual church service and, of course, family bonding. The best part? Prince George and Princess Charlotte are making their official Sandringham debut walking alongside their parents, Prince William and Kate Middleton. (In the past, they've waited inside for them. They're finally old enough!) See all of the photos from the festive day, ahead.