Philip Mountbatten married then-Princess Elizabeth in 1947 and the pair's marriage became the longest royal union in history. Just as his wife is the longest-serving British monarch, Prince Philip, the Duke of Edinburgh, was the longest-serving royal consort in British history. (According to tradition, the husband of a queen is known as a prince consort, and doesn’t become king.)

Despite the fact that Philip did not carry a role in his wife’s official duties, he provided Elizabeth with vital, continuous support. He also used his time in the Royal Family to shore up causes close to his heart, including sports, education and conservation.

Philip died on April 9, 2021 at the age of 99.

As third cousins—both great-great-grandchildren of Queen Victoria and her beloved consort, Prince Albert—the royal couple first crossed paths at family events, including King George VI’s coronation in 1937. But as Sally Bedell Smith writes in her 2012 biography, Elizabeth the Queen: Life of a Modern Monarch, sparks really flew (at least for the starry-eyed 13-year-old princess, known to her family as Lilibet) in the summer of 1939, when she and her family visited the Royal Naval College at Dartmouth, where Philip was a cadet.

The relationship developed over the course of World War II, during Philip’s service with the Royal Navy in the Mediterranean and the Pacific. In 1946, he proposed to Elizabeth at the royal family’s estate in Balmoral, Scotland, though at the insistence of King George VI, the engagement announcement was postponed until after his elder daughter turned 21.

In some respects, Philip was a traditional choice—he certainly had the royal pedigree. But in other ways, as Smith writes, the romance caused controversy. Palace courtiers and the aristocratic friends and relatives of the royal family viewed him as an irreverent foreigner—referring to him as “German” or even “Hun.” (Though Philip’s maternal grandfather, Prince Louis of Battenberg, was in fact German, the British royal family was no stranger to German bloodlines: Queen Victoria’s consort had been Prince Albert of Saxe-Coburg-Gotha, and during World War I King George V had changed the name of the royal house from Saxe-Coburg-Gotha to Windsor to minimize its German ties.)

Despite the controversy, they married in November 1947. In the first years of their marriage, the couple refurbished their official London residence, Clarence House; spent time in Malta, the Mediterranean island nation where Philip was serving with the Royal Navy; and had two children, Charles and Anne. The king’s declining health, however, changed everything. Elizabeth’s royal duties increased, and in 1951 Philip returned to London, effectively ending his promising naval career.

In February 1952, Elizabeth and Philip were at the beginning of a state visit to Kenya, then a British colony, when word came that King George VI had died at the age of 56. With his wife’s ascension to the throne at the age of 25, Prince Philip’s role of Queen’s consort began.

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It was a rocky transition period, including an embarrassing battle over Philip’s desire for his wife to take his mother’s family’s surname, Mountbatten (the English version of Battenburg), which Philip himself had only adopted recently, when he got his British citizenship and had to give up his title as prince of Greece. (He lost that battle, thanks to the opposition of his mother-in-law, the Queen Mother, and grandmother-in-law, Queen Mary, as well as Prime Minister Winston Churchill.)

Philip’s great-great-grandfather, Prince Albert, had exercised enormous influence during his wife’s reign, advising her on all kinds of political and diplomatic matters and even acting as her private secretary and manager of her affairs. In return, Victoria rewarded him with the official title of Prince Consort in 1857.

By contrast, Philip was excluded from his wife’s official duties, and didn’t take that official title. Despite this, Smith writes, Philip “resolved to support his wife while finding his own niche,” and patronizing organizations dedicated to such causes as sports (he was an avid polo player), education, wildlife conservation and the environment.

With his characteristic bluntness, Prince Philip also provided comic relief for his famously serious spouse over the years. He also raised eyebrows with some of his more controversial remarks, and made no secret of some of the shortcomings of his consort role.

“It was not my ambition to be president of the Mint Advisory Committee,” he told the Independent in 1992. “I didn’t want to be president of WWF. I was asked to do it…I’d much rather have stayed in the Navy, frankly.”

On his 90th birthday in 2011, Queen Elizabeth gave her husband the title of Lord High Admiral, titular head of the Royal Navy, in a gesture widely thought to be a recognition of the sacrifice he had made to stand by her side.

Philip formally retired from his royal duties in August 2017. He and Elizabeth were married for nearly 74 years—until his death in April 2021.

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