Prince Philip, the husband of Queen Elizabeth II, died April 9, 2021 at the age of 99. He married the future queen in 1947 and served steadfastly by her side for more than 70 years, as she became the longest-serving monarch in British history. As Duke of Edinburgh, Earl of Merioneth and Baron Greenwich, among many other titles, Philip was one of the busiest members of the royal family until he stepped away from his official duties in 2017. Since then, he underwent surgery on his hip and was involved in a traffic accident in which his vehicle hit another car and flipped over, though he was reportedly unhurt.

The British monarchy’s longest-running love story began just before the Second World War, when 18-year-old Prince Philip of Greece met his third cousin, Princess Elizabeth, the elder daughter of King George VI, during her family’s visit to the Britannia Royal Naval College at Dartmouth, where Philip was studying.

Then only 13 years old, Lilibet (as she was known to friends and family) was smitten by her tall, handsome older cousin immediately. She “never took her eyes off him,” Elizabeth’s longtime nanny, Marion “Crawfie” Crawford, later wrote of their first meeting, as quoted by the future queen’s biographer, Sally Bedell Smith, even though Philip “did not pay her any special attention.”

Born in 1921 on the Greek island of Corfu, Philip’s roots were as royal as they come: His father was Prince Andrew of Greece and Denmark, his paternal grandmother was a Romanov and his mother was the former Alice of Battenberg, a great-granddaughter of Queen Victoria.

But he had a difficult childhood, as political turmoil in Greece forced his family into exile in France when he was still an infant, and they lived in relative poverty (compared to other royals). All too soon, Philip’s parents split up; his mother went into a sanatorium, and later joined a religious order, while his father spent much of his time gambling in the South of France.

From age 10 on, then, the young prince spent much of his time at various boarding schools and with relatives. He lived in Germany for a time, but was sent back to England in 1934 to attend the Gordonstoun School, founded by Kurt Hahn, an intellectual who had fled Germany to avoid persecution by the Nazis. Under Hahn’s influence, Philip flourished at Gordonstoun, and would later insist on sending his eldest son, Prince Charles, who hated it.

In 1937, when Philip was 16, his sister Cecile, her husband and their children were killed in a plane crash. Philip flew to Germany and marched in their funeral procession, surrounded by fellow mourners in Nazi uniforms.

After his graduation from school, Philip joined the Royal Navy. After that first meeting with young Princess Elizabeth, the attachment between the two royal cousins grew during World War II, when Philip served with the Royal Navy in the Mediterranean and the Pacific. He was given a military award for his service on the HMS Valiant during the British victory over the Italian navy in the Battle of Cape Matapan in 1941, and emerged from the war as one of the Royal Navy’s youngest lieutenants.

In 1946, Philip proposed to Elizabeth at the royal family’s estate in Balmoral, Scotland. Despite Philip’s noble pedigree and stellar war record, his foreign status (including his sisters’ marital ties with prominent members of the Nazi Party) made him an outsider in royal circles, and a controversial choice of husband for the heir to the British throne.

On November 14, 1947, the couple were married in Westminster Abbey, and King George VI named Philip as Duke of Edinburgh shortly after that. Philip had given up his title of prince of Greece and taken his mother’s family surname of Mountbatten (the Anglicized version of Battenberg) when he became a British citizen.

During the early years of their marriage, Philip and Elizabeth had two children, Charles and Anne, and set up homes in a separate London residence, Clarence House, and on the Mediterranean island of Malta, where Philip continued his service in the Royal Navy. In 1950, he was given command of his own ship, the HMS Magpie.

But after Elizabeth’s father was diagnosed with lung cancer, the couple was called back so that she could take on an increased share of the royal duties. In early 1952, Philip and Elizabeth were traveling in Kenya, then a British colony, when they got word that King George VI had died at the age of 56.

Then just 25, Elizabeth would now become queen, decades earlier than the couple had expected. For Philip, his wife’s ascension to the throne meant making certain compromises. Though he had wanted his wife to take his name, Mountbatten, Elizabeth’s mother and grandmother, Queens Elizabeth and Mary, vetoed this idea, with the support of Prime Minister Winston Churchill. The young family also moved from Clarence House to Buckingham Palace, at Churchill’s insistence. (The couple would have two more sons, Andrew and Edward, in the 1960s.)

Most painfully, Philip was forced to give up his naval career. “It was not my ambition to be president of the Mint Advisory Committee. I didn't want to be president of WWF [World Wildlife Fund],” he told the Independent in 1992. “I'd much rather have stayed in the Navy, frankly.”

But his difficult childhood had left him with a strong sense of familial duty, which would serve him well as a royal consort. In June 1953, when his wife was crowned Queen Elizabeth II in a televised ceremony at Westminster Abbey, Philip knelt before her and solemnly pledged to become her “liege man of life and limb.”

According to British royal tradition, the husband of a queen doesn’t become king; he is officially known as a prince consort. But in 1957, a decade after they married, Queen Elizabeth made Philip an official prince of the United Kingdom, restoring the title he had given up before their marriage.

For more than a half-century, Prince Philip supported his wife in her royal duties and took on an ambitious slate of obligations of his own, averaging some 350 official engagements a year, according to one estimate. He also ran the queen’s estates, including a country home at Sandringham, Windsor Castle and Balmoral.

Gossip linked Prince Philip to various other women over the years, including the actress Pat Kirkwood, the author Daphne du Maurier and Philip’s childhood friend, the cabaret star Hélène Cordet. But such reports were always strenuously denied, and no evidence ever surfaced proving an affair.

Perhaps most famously, Prince Philip earned a reputation for his conservative views and his plainspoken candor. The press once referred to him as a “national treasure,” and his plainspoken candor made some people laugh, many others cringed at his more controversial, casually racist gaffes.

In 2017, Prince Philip stepped away from his public duties, after having maintained one of the busiest schedules of all of the royals. According to a statement issued at the time, then 96-year-old Philip was “patron, president or a member of over 780 organisations, with which he will continue to be associated, although he will no longer play an active role by attending engagements.” That November, Prince Philip and Queen Elizabeth celebrated their 70th wedding anniversary.

News broke in early 2019 that Prince Philip had been involved in a car crash while driving near the royal estate at Sandringham, when his Land Rover hit another car and overturned. Two women in the Kia were treated at a hospital and released with minor injuries. Though his windshield shattered, the duke was reportedly unhurt, and was seen driving several days later (not wearing a seatbelt).

In February 2021, Philip was admitted to King Edward VII Hospital in London. Buckingham Palace said in a statement that it was a precautionary measure recommended by his doctor after Philip was feeling unwell. Philip had returned home to Windsor Castle in March.

On April 9, 2021, a notice from the Royal Family announced, "His Royal Highness passed away peacefully this morning at Windsor Castle."