Charles Ascends to a Role He Has Prepared for All His Life

LONDON — Never, perhaps, has an heir been more ready for the crown.

Charles, the eldest son of Queen Elizabeth II and a man born to be king, acceded to the throne on Thursdayafter being the designated successor for longer than anyone in the history of the British monarchy. In those seven decades, Charles struggled to chart his own path, survived scandal and heartbreak, and found a new tranquillity — all played out in the remorseless glare of the world stage.

Having aged from an awkward, self-doubting young man into an unhappy middle-aged husband, Charles has become, at 73, a self-assured, gray-haired eminence, steeped in causes like climate change and environmental protection, which were once quirky but now seem peculiarly in sync with the times.

Whether Charles will ever enjoy the respect or affection showered on his mother is another question. Thrust on to the throne at 25, Elizabeth reigned for longer than most Britons have been alive, anchoring her country with stoic dignity as it made a turbulent passage from globe-spanning empire to reluctant member of the European Union to an uncertain future after Brexit.

Charles’s journey was, perhaps inevitably, less acclaimed. His foibles and frustrations were mercilessly dissected by the news media; his pet hobbies, from architecture criticism to organic farming, were frequently mocked; his marriage to Diana, Princess of Wales, which crumbled amid lurid tabloid headlines and mutual charges of infidelity, remains for many the defining event of his public life.

At the nadir of Charles’s public life, in the mid-1990s, some critics went so far as to say that the scandal-scarred heir had forfeited the right to be king and that the crown should skip a generation, going to his elder son, Prince William, who was untarnished by public blemishes.

Nothing, of course, compared to his marriage to Diana. The seamy tabloid stories, the tell-all TV interviews (“There were three of us in this marriage,” Diana said to the BBC, referring to her husband and Camilla Parker-Bowles, whom he later married), the bitter divorce and Diana’s death in a car crash in Paris in 1997 — all of it crystallized the image held by many of Charles as an oafish cad and his family as unfeeling in-laws.

From 1991 to 1996, the percentage of people who said they thought Charles would make a good king plunged to 41 percent from 82 percent, according to the polling firm MORI. But Diana’s death proved a turning point: Charles worked with Tony Blair, the prime minister at the time, to nudge his mother into honoring Diana’s memory, amid a national outpouring of grief, and then set about rehabilitating his own image.

He has mostly succeeded. Few Britons now recoil at the prospect of King Charles III, even if he sometimes seems more a fuddy-duddy uncle than a national patriarch.

Married since 2005 to Camilla, with whom he was romantically involved before and during his marriage to Diana, Charles has found stability in his personal life. With the death of his father, Prince Philip, at 99, last year, he became paterfamilias of the House of Windsor. Camilla, 74, who will take the title of queen, is a sturdy and respectable presence at his side.

But Charles takes the helm of a royal family that has been rocked by a series of upheavals: a bitter falling-out with his younger son, Prince Harry, and his American-actress wife, Meghan, and the unsavory ties of his brother, Prince Andrew, with the financier Jeffrey Epstein, which resulted in a civil suit against Andrew accusing him of sexual abuse of a teenager. Charles has struggled to keep wayward family members in line.

He has also long pushed to streamline the monarchy, partly to reduce its drain on the public purse. As king, he will be able to put that plan fully into action. The end of the second Elizabethan Age thus promises to be a momentous transition, not just because of the passing of a beloved queen but also because Charles will bring his own ideas into a job for which he has spent a lifetime preparing.

“The style will be very different,” said Vernon Bogdanor, a professor of government at King’s College London who has written about the role of the monarchy in Britain’s constitutional system. “He will be an active king and he will probably push his prerogatives to the limits, but he won’t go beyond them.”

Charles, he said, fought to carve out an identity as the Prince of Wales, a role that he held longer than anyone but that comes without a job description. He founded formidable charities like the Prince’s Trust, which has helped nearly a million disadvantaged young people, and championed causes like sustainable urban planning and environmental protection, long before they became fashionable.

In recent years, he has taken on several of the queen’s duties, from foreign trips to investitures, where people are granted knighthoods. On Remembrance Day, he placed a wreath at the monument to Britain’s fallen soldiers on her behalf. At the state opening of Parliament, he escorted her into the Palace of Westminster.

Charles has also not hesitated to wade into fraught political issues. He has spoken out regularly for religious tolerance and against Islamophobia, which some credit with helping mute a potential backlash against Muslims after a series of deadly terrorist attacks carried out by Islamic extremists in London in 2005.

“He could have spent his time in nightclubs or doing nothing at all, but he’s found a role,” said Professor Bogdanor.

At times, Charles’s strong opinions have gotten him into hot water. In 1984, he famously ridiculed a proposed extension to the National Gallery as a “monstrous carbuncle on the face of a much-loved and elegant friend.” The plan was scrapped, but years later, prominent architects complained that his backdoor lobbying against designs that he did not favor was an abuse of his constitutional role.

In 2006, Charles raised hackles when a British tabloid, The Mail on Sunday, published extracts from a diary he kept while representing the queen at Britain’s formal handover of Hong Kong to China in 1997. He described the Chinese officials on hand as “appalling waxworks” and said that after a “propaganda speech” by the Chinese president, Jiang Zemin, “We had to watch the Chinese soldiers goose-step on to the stage and haul down the Union Jack and raise the ultimate flag.”

Charles won a court ruling against The Mail’s publisher for violating his privacy rights.

As king, Charles will have to keep his opinions to himself. His mother was so discreet that royal watchers could not decipher her positions even on furiously debated issues like Brexit. Charles, too, was careful not to opine on Brexit, though he gave a glimpse into his thinking when he told the German Parliament in 2020 that “no country is really an island” and pleaded for Germany to keep working with Britain.

It is not clear whether Charles will continue his extensive philanthropy. He is a patron or president of more than 400 charities, in addition to the Prince’s Trust. But his philanthropic work has not been without problems: The chief executive of another of Charles’s charities, Michael Fawcett, resigned after he was accused of promising to obtain a knighthood for a billionaire Saudi donor.

For some, the scandal laid bare one of Charles’s biggest weaknesses: a lack of judgment about those around him. Advisers had long questioned the conduct of Mr. Fawcett, who had served as the prince’s valet before ascending into powerful posts in his charity network. But Charles, whose spokesman said he had not been aware of the cash-for-honors accusation, hung on to Mr. Fawcett stubbornly.

Charles is still not overly popular. Last year, he was picked as the favorite member of the royal family by just 11 percent of those surveyed, according to Ipsos MORI, trailing the queen; William and his wife, Kate; Harry and Meghan; Princess Anne; Prince Philip; and any of the queen’s great-grandchildren.

But for now, the future of the monarchy seems secure: 43 percent of people said Britain would be worse off without it, while only 19 percent said it would be better off, and 31 percent said there would be no difference. Those numbers barely budged even after Harry and Meghan gave a sensational interview to Oprah Winfrey in which they accused the royal family of callous and racist treatment.

For Charles, the biggest personal challenge may be healing the rift with his son. Harry told Ms. Winfrey that his father had stopped taking his calls for a while. “There’s a lot of hurt that has happened,” Harry said. There is little sign of a reconciliation, and Harry is writing a memoir that people close to Buckingham Palace fear will reopen the wounds from the couple’s split with the family.

Charles must also deal with the legal fallout from his brother Andrew’s relationship with Mr. Epstein. He moved swiftly to sideline Andrew from royal duties after his brother gave a damning interview to the BBC in a misbegotten effort to clear his name. Royal watchers said it was a sign, even before his mother died, that Charles was cementing his role as the leader of the family and a king in waiting.

“He has grown in stature in recent years,” said Penny Junor, a royal historian. “He’s looking like a much more confident character, happier in his own skin.”