A police officer stands guard on the door outside King Edward VII's Hospital in London on June 21, 2017 where Britain's Prince Philip in receiving treatment. Prince Philip, the 96-year-old husband of Queen Elizabeth II, has been admitted to hospital as a "precautionary measure" for treatment of an infection, Buckingham Palace said on June 21. The infection arose from "a pre-existing condition", the palace said. / AFP PHOTO / NIKLAS HALLE'N (Photo credit should read NIKLAS HALLE'N/AFP/Getty Images)
