Queen Elizabeth II paid tribute to her husband, Prince Philip, who turned 95 on Friday, the same day that Britain held a national service to mark the queen's official 90th birthday.
"He has, quite simply, been my strength and stay all these years," the queen said in a brief statement on Prince Philip's birthday.
The royal family published a commemorative portrait of the couple, who married 68 years ago, by celebrity photographer Annie Leibovitz. Leibovitz also took three portraits of the queen to mark her actual birthday on April 21.
The queen's engagement to Lieutenant Philip Mountbatten, a naval officer descended from Danish, Greek and German royalty, was announced in 1947, and the couple married a few months later at London's Westminster Abbey. He was given the titles Prince Philip and Duke of Edinburgh.
The queen and Prince Philip have four children: Charles, Anne, Andrew and Edward.