Prince Philip remembered: Boris Johnson leads tributes to Duke of Edinburgh

World leaders pay tribute to Prince Philip, who died Friday at the age of 99 at Windsor Castle.

With flags lowered to half-mast, Johnson said the news of the Duke’s death was received "with great sadness" and honored his memory as one of the last survivors to have served in the Second World War. "From that conflict, he took an ethic of service that he applied throughout the unprecedented changes of the post-War era," Johnson said, adding: "He helped steer the Royal Family and the monarchy so that it remains an institution indisputably vital to the balance and happiness of our national life."  Johnson continued: "We remember the Duke for all of this and above all for his steadfast support for Her Majesty the Queen." Johnson went on to express Britain lost a "highly respected public figure" remembered as a  "devoted husband and a proud and loving father, grandfather and in recent years, great grandfather."