Britain's King Charles III was crowned on Saturday in the country's biggest ceremonial event for seven decades, a sumptuous display of pageantry dating back 1,000 years.

In front of a congregation of about 100 world leaders and a television audience of millions, the Archbishop of Canterbury, the spiritual leader of the Anglican Church, slowly placed the 360-year-old St Edward's Crown on Charles' head as he sat upon a 14th-century throne in Westminster Abbey.

The historic and solemn event dates back to the time of the 74-year-old's predecessor William the Conqueror in 1066.

Charles' second wife Camilla, 75, will be crowned queen during the two-hour ceremony.

For a nation struggling to find its way in the political maelstrom after its exit from the European Union and maintain its standing in a new world order, its supporters say the royal family provides an international draw, a vital diplomatic tool and a means of staying on the world stage.

"No other country could put on such a dazzling display – the processions, the pageantry, the ceremonies, and street parties," Britain's Prime Minister Rishi Sunak said.

Despite Sunak's enthusiasm, the coronation takes place amid a cost of living crisis and public skepticism, particularly among the young, about the role and relevance of the monarchy.

Charles automatically succeeded his mother Queen Elizabeth II as king on her death last September, and the coronation is not essential but regarded as a means to legitimize the monarch in a public way.

Hundreds of soldiers in scarlet uniforms and black bearskin hats lined the route along The Mall, the grand boulevard to Buckingham Palace. Tens of thousands ignored the light rain to watch what some saw as a moment of history.

However, not all were there to cheer Charles. Hundreds of republicans booed and waved banners reading "Not My King." More than 11,000 police were deployed to stamp out any attempted disruption.

(With input from Reuters)