The monarch traveled to the abbey from Buckingham Palace in a gilt-trimmed, horse-drawn carriage, the final mile of a seven-decade journey from heir to monarch.
More than 2,000 guests, thousands of troops, tens of thousands of spectators, and a smattering of protesters converged in and around the abbey as the king and his wife, Camilla, passed by.
The ceremony will be filled with pomp and pageantry: There will be crowns and diamonds, soaring music, purple robes, magnificent hats — and a rousing cheer of “God Save the King” inside the abbey and in the streets outside.
As guests arrived, the church buzzed with excitement and was abloom with fragrant flowers and colorful hats. Streaming into the abbey were celebrities, dignitaries, and world leaders, including U.S. First Lady Jill Biden, French President Emmanuel Macron, Canadian Prime Minister Justin Trudeau, eight current and former British prime ministers as well as Judi Dench, Emma Thompson, and Lionel Richie.
Thousands of people from across the U.K. and around the world camped overnight along a 1.3-mile (2-kilometer) route.
The crowds grew during the morning, in intermittent rain, along the route, which the newly crowned king and queen will take back to the palace, this time in a 261-year-old gilded carriage accompanied by 4,000 troops, forming Britain’s biggest military parade in 70 years.
To the royal family and government, the occasion — code-named Operation Golden Orb — is a display of heritage, tradition, and spectacle unmatched around the world.
Dean of Westminster David Hoyle who will help lead the service, predicted it would be spectacular.
“I’m used to ceremony on a national level. Even I think this is pretty jaw-dropping,” he said.
But to Republican protesters who gathered to holler “ Not my king,” it’s a celebration of an institution that stands for privilege and inequality.
The anti-monarchy group Republic said six of its members, including its chief executive, were arrested as they arrived at the protest. Police have said they will have a “low tolerance” for people seeking to disrupt the day, sparking criticism that they are clamping down on free speech.
For 1,000 years and more, British monarchs have been crowned in grandiose ceremonies that confirm their right to rule.
These days, the king no longer has executive or political power, and the service is purely ceremonial since Charles automatically became king upon death of his mother, Queen Elizabeth II, in September.
The king remains the U.K.’s head of state and a symbol of national identity — and Charles will have to work to unite a multicultural nation at at time when reverence for the monarchy has been replaced, for many, with apathy.
Double-digit inflation is also making everyone in the U.K. poorer, raising questions about the cost of all the pomp.
Charles has sought to lead a smaller, less expensive royal machine for the 21st century. So this will be a shorter affair than Elizabeth's three-hour coronation.
In 1953, Westminster Abbey was fitted with temporary stands to boost the seating capacity to more than 8,000, aristocrats wore crimson robes and coronets, and the coronation procession meandered 5 miles (8 kilometers) through central London so an estimated 3 million people could cheer for the glamorous 27-year-old queen.
Organizers this time have shortened the procession route, trimmed the coronation service to less than two hours, and sent out 2,300 invitations to world royalty, heads of state, public servants, key workers, and local heroes.
There were judges in wigs, soldiers with gleaming medals attached to red tunics, and members of the House of Lords in their red robes.
The king's family will be on hand, including his sparring sons Prince William and Prince Harry — though not Harry's wife Meghan, and their children, who remain at home in California.
Built around the theme “Called to Serve,” the coronation service will begin with one of the youngest members of the congregation — a boy chorister — greeting the king. Charles will respond by saying, "I come not to be served but to serve.”
The moment is meant to underscore the importance of young people — and is a new addition to a service laden with the rituals through which power has been passed down to new monarchs throughout the centuries.
The symbolic peak of the two-hour service will come halfway through when Archbishop of Canterbury Justin Welby places the solid gold St. Edward’s Crown on the monarch’s head. Trumpets will sound and gun salutes will be fired across the U.K.
In another change, Charles scrapped the traditional moment at the end of the service when nobles were asked to kneel and pledge their loyalty to the king.
Instead, Welby will invite everyone in the abbey to swear “true allegiance” to the monarch. He'll invite people watching on television to pay homage, too — though that part of the ceremony has been toned down after some criticized it as a tone-deaf effort to demand public support for Charles. Welby will now suggest people at home take a “moment of quiet reflection” or say “God Save the King.”
The public’s response to Charles, though, during the service and along the parade route, is key, said George Gross, a visiting research fellow at King’s College, London, and an expert on coronations.
“None of this matters if the public doesn’t show up,’’ Gross said. ‘’If they don’t care, then the whole thing doesn’t really work. It is all about this interaction.’’
And today's public is very different from the audience that saw Elizabeth crowned.
Almost 20% of the population now comes from ethnic minority groups, compared with less than 1% in the 1950s. More than 300 languages are spoken in British schools, and less than half of the population describe themselves as Christian.
Although organizers say the coronation remains a “sacred Anglican service,” the ceremony will for the first time include the active participation of other faiths, including representatives of the Buddhist, Hindu, Jewish, Muslim, and Sikh traditions.