More than 20,000 solo appearances

Through the Queen's 69 years on the throne, the man whom she had called her "strength and stay" carried out more than 22,000 solo engagements and made nearly 5,500 speeches. He attended events periodically with the Queen and other members of the Royal Family after stepping back from official duties.

The Queen and Prince Philip mark her 90th birthday in Windsor, England. Elizabeth, Britain's oldest and longest-reigning monarch, turned 90 on April 21, 2016. (Annie Leibovitz/Buckingham Palace/The Associated Press)

Often viewed as a gruff curmudgeon prone to gaffes that grabbed the headlines, the 99-year-old royal was also a guiding force for the House of Windsor and sought to introduce more modern practices into an institution steeped in tradition.

"What Prince Philip did was help modernize the monarchy in the 1950s," Michael Jackson, president of the Institute for the Study of the Crown in Canada, said in an interview Friday morning.

"It was still a very tradition-bound institution…. We can credit Prince Philip, with the Queen's full support, of course, of modernizing [its] finances, protocols, how Buckingham Palace was run … its outreach to the Commonwealth."

Philip had been in hospital several times in recent years, including for hip replacement surgery in April 2018 and for treatment of a pre-existing condition in December 2019. He was in hospital for about a month earlier this year, returning to Windsor Castle in mid-March.

While he had retired from public duties, Philip found himself back in the public eye and at the centre of controversy in early 2019 after a Land Rover he was driving collided with a car near Sandringham, the royal estate in eastern England. 

• Royal Family's book of condolence for Philip

Philip wasn't hurt, but his vehicle rolled over, and a woman in the car suffered a broken wrist. He eventually apologized to her and said he had been dazzled by the sun while turning onto a main road. He also gave up his driver's licence.

Pictures of him with the Queen were released occasionally over the past year, including at the time of his 99th birthday last June and for their 73rd wedding anniversary in November. During the pandemic lockdown, he and the Queen had been staying at Windsor Castle. 

John Fraser, author of The Secret of the Crown: Canada's Affair with Royalty, credits Philip's profoundly unsettled early years with how he looked toward the future of the Royal Family, and the monarchy.

"I do think those early years were the single biggest factor in his life and how he approached life," said Fraser. "I think he never assumed things would last forever because he didn't make any assumptions like that, and I think he certainly assumed the monarchy wouldn't survive if it didn't reach out more to the constituency that it had to serve."

Royal connections

Philip was born a prince of both Greece and Denmark on June 10, 1921, on the dining room table at his parents' home in Mon Repos, on the Greek island of Corfu.

Despite his birthplace, he had no Greek ancestry. His family tree includes members of the royal families of Denmark, Germany, Russia and Britain.

The Greek royal family was forced into exile in 1922 when Philip was 18 months old.

His father was Prince Andrew of Greece, whose own father was the grandson of King Christian IX of Denmark. Philip's mother was Princess Alice of Battenberg, the eldest child of Prince Louis of Battenberg and the sister of Earl Mountbatten of Burma.

WATCH | Former governor general David Johnston recalls spending time with Philip and Elizabeth:

Unsettled childhood

For Philip, it was an unstable, unsettled childhood. The family broke down, with his mother ill periodically and in a sanitorium. His father went off to Monte Carlo with his mistress.

As a boy, Philip attended schools in England, Germany and Scotland before joining the Royal Naval College at Dartmouth, England, as a cadet, in 1939.

Through his uncle, Louis Mountbatten, the 18-year-old Philip was introduced to British royal circles. At that point, he met a 13-year-old Princess Elizabeth, his third cousin: both had Queen Victoria as a great-great-grandmother.

When the Second World War broke out, he focused on his naval career and quickly rose through the ranks. At just 21, he was appointed first lieutenant (second in command) of the destroyer HMS Wallace, which took part in the Allied landings at Sicily.

When he returned home in January 1946, Philip, who had kept in touch with Elizabeth, began courting the young princess. Their engagement was announced 18 months later.

Although most of the public embraced the union, some were unhappy with Philip's un-British origins, and many began referring to him as "Phil the Greek." He silenced those critics when he became a British citizen in 1947 and renounced his Greek royal titles. He became Lt. Philip Mountbatten.

He and Elizabeth were married on Nov. 20, 1947, at Westminster Abbey in a wedding that helped boost British spirits still recovering from the war. He was designated a royal highness, created a knight of the Garter and awarded the title Duke of Edinburgh.

WATCH | Archive footage of Elizabeth and Philip's wedding at Westminster Abbey: 

Naval commander

Assuming his new royal role, Philip continued to be appointed and promoted to different positions in the navy. By 1952, he had reached the rank of commander.

His naval career came to an end that year when, on a trip to Kenya, Princess Elizabeth received news that her father, King George VI, had died and that she had become Queen.

As husband of the sovereign, Philip was not crowned at the coronation ceremony in 1953.

Prince Philip and Queen Elizabeth wave from a balcony at Buckingham Palace following her coronation at Westminster Abbey on June 2, 1953. (The Associated Press) 

Although his active role with the navy was finished, he continued his involvement in the armed forces. He was appointed admiral of the Sea Cadet Corps, colonel-in-chief of the Army Cadet Force and air commodore-in-chief of the Air Training Corps. In 1953, he also had the duties of admiral of the fleet, field marshal and marshal of the Royal Air Force.

In February 1957, he was awarded the titular dignity of Prince of the United Kingdom and became known as Prince Philip, Duke of Edinburgh.

While carving out an independent role from the Queen, he also established a reputation for blunt, controversial and sometimes offensive or racist statements.

In 1966, he sparked outrage when he said, "British women can't cook." During a visit to China in 1986, he described Beijing as "ghastly" and told British students: "If you stay here much longer, you'll all be slitty-eyed."

He told a Briton he met in Hungary in 1993: "You can't have been here that long, you haven't got a pot-belly."

In Australia in 2002, the prince asked an Aborigine if "you still throw spears at each other."

He also dismissed stress counselling for servicemen in a TV documentary on the 50th anniversary of D-Day, saying, "It was part of the fortunes of war. We didn't have counsellors rushing around every time somebody let off a gun, asking, 'Are you all right? Are you sure you don't have a ghastly problem?' You just got on with it."

Prince William told the BBC in November 2004 that he admired his grandfather's occasional bluntness.

"He will tell me something I don't want to hear and doesn't care if I get upset about it."

Under scrutiny after Diana's death

Philip came under intense scrutiny after Diana, Princess of Wales, the ex-wife of Philip and Elizabeth's eldest son, Prince Charles, died following a Paris car crash with her companion, Dodi Fayed, in 1997.

Philip and the rest of the Royal Family went into seclusion after the accident, but Philip later made a strong statement at Diana's funeral, walking with his family behind her casket as it was carried on a carriage through the streets of London.

After the funeral, Fayed's father, the powerful Egyptian businessman Mohammed Al-Fayed, blamed Philip for the crash. He accused Philip of ordering British secret service agents to kill Diana and Fayed because Philip didn't want Diana to marry a Muslim.

An inquest into the accident cleared Philip of any wrongdoing, blaming the crash instead on the negligent driving of Diana and Fayed's chauffeur and the paparazzi who were chasing them.

The late Diana, Princess of Wales, at Aintree racecourse in April 1982. After Diana's death in 1997, Philip was the subject of some of the speculation about what caused the car crash that killed her but was cleared of any wrongdoing. (Hulton Archive/Getty Images)

 Although Philip reportedly had a heart condition, he maintained a busy pace and in recent years enjoyed relatively good health, punctuated by some trips to hospital. In June 2010, he underwent surgery on his left hand for carpal tunnel syndrome. He was treated in 2008 for a chest infection.

Philip spent four nights in hospital over Christmas in 2011 recovering from a successful coronary stent procedure. Nearly six months later, he missed half the Queen's Diamond Jubilee celebrations after he was taken to hospital with a bladder infection. He later spent five days in a Scottish hospital for the same problem.

On June 2, 2013, he was admitted to a London hospital for exploratory abdominal surgery. Returning to his duties two months later, he declared it was a "great pleasure to be back in circulation."

Philip served as president or patron of nearly 800 organizations, and he attended an average of 370 official engagements annually.

Prince Philip gestures as he speaks after attending the annual Commonwealth Observance at Westminster Abbey on March 9, 2015. The observance is the biggest multifaith celebration in the U.K. (The Associated Press)

 For recreation, he enjoyed sailing, cricket and carriage-driving. When he was younger he also played polo, but said age forced him to take up carriage-driving, which he jokingly called a "geriatric sport."

Despite his busy schedule, he accompanied the Queen on her Commonwealth tours and state visits overseas, as well as on tours and visits to all parts of the United Kingdom. He visited Canada more than 70 times, coming with the Queen on several occasions, and other times on his own. The Queen and Prince Philip's last trip to Canada together was in the summer of 2010. 

WATCH | Philip visits Canada in 1954:

In April 2013, Philip made an unexpected solo visit to Toronto, where he presented a new ceremonial flag to the Royal Canadian Regiment's 3rd Battalion. He had served as the regiment's colonel-in-chief since 1953. During that brief visit, he was also awarded the highest level of the Order of Canada by Gov. Gen. David Johnston.

He was steadfast in his support of the Queen, spending his public life two paces behind her, but always ready to help when needed. Those who knew the royal couple well say the Queen often deferred to Philip in private.

During celebrations for her Golden Jubilee on the throne in 2002, the Queen offered a tribute to the royal consort.

"He has quite simply been my strength and stay all these years," she told the crowds.

Prince Philip stands with Princess Elizabeth and their children Prince Charles and Princess Anne at the couple's London residence at Clarence House in August 1951. Elizabeth became Queen in 1952. (The Associated Press)

 "And I and his whole family and this and many other countries owe him a debt greater than he would ever claim or we should ever know."

In 2011, the Royal Mint, to mark Prince Philip's 90th birthday, issued a commemorative £5 coin featuring a portrait of Prince Philip on one side and the Queen on the other. It was the first time a reigning monarch and consort appeared on opposite sides of a U.K. coin.

Prince Philip leaves three sons and a daughter, eight grandchildren and 10 great-grandchildren.

WATCH | British Prime Minister Boris Johnson pays tribute to Philip: