Prince Philip, the longest-serving consort in British history and lifelong companion of Queen Elizabeth the second, died at Windsor Castle on Friday, local time.
He was 99 years old and had been married to the queen for 73 years.
The cause of death has not yet been disclosed, but it comes after a period of poor health in recent years, including heart surgery.
Buckingham Palace says the Duke of Edinburgh died peacefully and that further announcements will be made in due course.
At the Duke's request, there will be no state funeral.
Instead, a royal funeral will be held at St George's Chapel.
Tributes have poured in from across the globe, including the United States and the Commonwealth nations of India, Australia, and Canada.