Prince Philip waves as he leaves King Edward VII Hospital in central London on Saturday, June 9, 2012, after being treated for a bladder infection. He will celebrate his 91st birthday Sunday privately with members of the royal family. (AP Photo/Press Associaiton, Max Nash)

Photo by: Max nash

Prince Philip waves as he leaves King Edward VII Hospital in central London on Saturday, June 9, 2012, after being treated for a bladder infection. He will celebrate his 91st birthday Sunday privately with members of the royal family. (AP Photo/Press Associaiton, Max Nash)