King Charles III and Queen Camilla have arrived.On Sunday, the newly-crowned royals got a royal welcome as the trumpets sounded from the stage and they were spotted arriving at their seats inside the grounds of Windsor Castle.Charles and Camilla — who arrived earlier than expected — were greeted with cheers and applause from the over 20,000 attendees inside the venue.As they made their way, Kate Middleton and Princess Charlotte curtsied as a sign of respect. Also joining them in the box were Prince William and Prince George, as well as other immediate members of the family.The royals had mini Union Jack flags to wave as they took in the show.Sunday's coronation concert is shaping up to be a big event.