King Charles arrives at Westminster Abbey for coronation

King Charles III arrived at London's Westminster Abbey on Saturday to be crowned in Britain's biggest ceremonial event for seven decades, a sumptuous display of pageantry dating back 1,000 years.

Charles succeeded his mother Queen Elizabeth when she died last September and at 74, he will become the oldest British monarch to have the 360-year-old St Edward's Crown placed on his head as he sits upon a 14th century throne at London's Westminster Abbey, reports reuters.

The king and his second wife Camilla, 75, who will be crowned queen during the two-hour ceremony, left Buckingham Palace in the modern, black Diamond State Jubilee Coach accompanied by cavalrymen wearing shining breastplates and plumed helmets.

In the abbey, watched by about 100 heads of state and dignitaries, including U.S. first lady Jill Biden, and millions on television, Charles be crowned as his predecessors have been from the time of William the Conqueror in 1066.

While rooted in history, the event will also attempt to present a forward-looking monarchy.

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 still provides an international draw, a vital diplomatic tool and a means of staying on the world stage.

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

Saturday's event will be on a smaller scale than that staged for Queen Elizabeth in 1953, but will still aim to be spectacular, featuring an array of historical regalia from golden orbs and bejewelled swords to a sceptre holding the world's largest colourless cut diamond.