Philip, whose title was the Duke of Edinburgh, had in the past few years suffered through a handful of illnesses, some of which resulted in his being hospitalized. He was in the hospital in February of this year, undergoing treatment for a pre-existing heart condition. He died peacefully at Windsor Castle, on April 10.

Tributes poured in from around the U.K. and around the world. The royal family announced a statement that said, in part, "It is with deep sorrow that Her Majesty The Queen announces the death of her beloved husband." Buckingham Palace officials lowered the flag to half-staff, and the tenor bell at Westminster Abbey tolled once a minute for 99 minutes to mark Philip's life. The Government ordered all flags at all official buildings to fly their flags at half-staff as well.

He was born on Corfu, a Greek island, on June 10, 1921. He was the only son of Prince Andrew of Greece and Denmark and Princess Alice, and he was the nephew of King Constantine of Greece. Philip's bloodline had a direct connection to Queen Victoria in that his mother was that former monarch's great-granddaughter.

Philip's parents separated when the boy was young, and he went to England to live with his maternal grandmother, the Dowager Marchioness of Milford Haven. He had learned English as his first language and attended the Cheam School in England and the Gordonstoun School in Scotland.

In 1939, Philip first attended the Britannia Royal Naval College, at Dartmouth. He went to war the following year, serving aboard the battleships Ramillies and Valiant. His wartime experiences included playing a vital role in a 1941 naval victory against Italy and joining in the 1943 Allied landings in Sicily.

Philip's uncle, Louis Mountbatten, was the supreme allied commander in Southeast Asia during the latter part of the war, and both were onboard the United States battleship USS Missouri when Japan formally surrendered to the U.S., on Sept. 2, 1945, ending World War II.

Philip and Elizabeth had met a handful of times during the war. He stayed at Windsor Castle while on leave, and she was there. She was a teenager and in attendance on the royal yacht when he dined there. Many sources say that after one visit of Philip's to the royal residence at Balmoral, Elizabeth told her father, King George VI, that she would love Philip and no other.

They got engaged on July 10, 1947, and got married on November 20 of that same year; he was 26 and she was 21. About 2,000 people attended their wedding, which was at Westminster Abbey; a live radio broadcast of the service had an estimated 200 million listeners.

Charles, the first child of Philip and Elizabeth, was born in 1948. Two years later came Anne. Andrew was born in 1960, and Edward rounded out the family four years later. Uncustomarily for the time period, Philip played a large role in the rearing of his children.

Elizabeth became the reigning monarch on Feb. 6, 1952, when her father died and she and Philip were in Kenya, on a commonwealth tour. Queen Elizabeth II named her husband "the first gentleman of the land" and appointed him to the highest-ranking positions in the U.K. armed services, in all of which he served without drawing a salary.

Philip was part of a few efforts to modernize the royal family. He answered the telephone himself and routinely carried his own luggage. He was the first member of the royal family to appear in a television interview and played a large role in the presentation of a 1969 TV documentary on the royal family.

He was the first member of the United Kingdom royal family to visit to the Soviet Union, accompanying the U.K. equestrian team in 1973 as a stand-in for the queen.

Philip adopted as causes science and technology (founding the Royal Academy of Engineering), and environmental issues (serving as the first president of the World Wildlife Fund). Another of his well-known initiatives was a group that helped schoolchildren in the U.K. take part in challenging outdoor adventures. He was the patron and founder of many charities. His interests included industrial design and modern art.

The duke was known for his bluntness, and some public comments got him in trouble from time to time. He retired from public life in 2017, having serving more than 22,000 royal engagements in his seven decades as the spouse of the monarch. He was the longest-serving consort ever, dating to the earliest years of England. He achieved this status in 2009, eclipsing Queen Charlotte, the wife of King George III.

Surviving Philip, in addition to his wife and four children, are eight grandchildren and 10 great-grandchildren.