Prince Harry and Meghan Markle have united with Prince William and Kate Middleton for a surprise visit to inspect floral tributes outside Windsor Castle for the Queen on Saturday 10 September.The Prince and Princess of Wales and the Duke and Duchess of Sussex were dressed in all black as they walked along the gates of Windsor Castle.The Duke and Duchess of Sussex held hands as they looked at the tributes, with Harry at one point affectionately putting his hand on Meghan’s back.They were seen pointing at different tributes and discussing them as members of the crowd waved at them. Read More Related Articles Prince William's tear-jerking tribute to 'Grannie': 'She was by my side at my saddest moments' A crowd at Windsor Castle broke out into applause as the Prince and Princess of Wales and the Duke and Duchess of Sussex approached members of the public and spoke to them.