On Saturday morning The first coronation in 70 years is to take place when King Charles III, the Queen Consort and their carriage will make a historic trip to Westminster Abbey.

Despite forecasts of rain, crowds have already begun to gather on the procession route.

The central London area will be under a massive security operation, and 100 heads of state are expected to attend.

Those who oppose the monarchy have promised protests.

The Coronation service, which will last almost two hours, will be seen first-hand by 2,300 guests, including Prince Harry, the Duke of Sussex, who arrived from the United States on Friday on a commercial flight.

It will be the first time since the release of Prince Harry's memoir that he will have been seen in public with his brother, Prince William, the Prince of Wales.

Prince Harry is expected to fly back to America within hours of the ceremony in order to join his wife Meghan.

Charles was crowned king of England and 14 other countries in September when his mother Elizabeth passed away after 70 years as queen. The coronation celebrations at Westminster Abbey, the 40th since 1066, have been planned for months.

The King appeared relaxed on the Mall on the day before the Coronation. He was flanked by Prince Charles and Princess Diana, as well as a large security detail.

Barbara Crowther, 69, and her friend Pauline, joined the crowds holding a "Coronation Street" banner.

"We weren't going to camp, but there are so many people here, we thought that if we don't camp out, we won't get anywhere near the front," said Ms Crowther.

Katie Gordon, from Wiltshire, was painting faces with her two daughters on Friday. She thinks the new King and Queen are "going to be great".

"We're camping out tonight ready for the Coronation, and they're painting everyone's faces as they walk by," Ms Gordon said.

"We're doing it for free, it's just something we're doing. We bought the facepaints for ourselves and thought, why not do it for other people too?

As the sun set on Friday, hundreds of tents had appeared along the Coronation route, with those gathered hoping to witness the historic event.

The Archbishop of Canterbury, Justin Welby, will preside over the service, with guests ranging from US First Lady Jill Biden to President Macron of France and entertainers Ant and Dec.

Olena Zelenska, wife of the Ukrainian president Volodymyr Zelensky, met Catherine, Princess of Wales at a pre-Coronation reception at Buckingham Palace on Friday.

Charles was photographed sharing warm words with the First Lady of Ukraine, and greeting Mary, Crown Princess of Denmark, with a handshake and a kiss on the cheek.

There has been controversy over whether people at home were being asked to pledge their allegiance to the King.

The Church of England has made clear this is entirely optional and people might instead have a "private moment of reflection".

The keynote message of the Coronation from King Charles is in his first prayer when he reaches the Abbey reads: "I come not to be served, but to serve."

The high point of the ceremony will come when the St Edward's Crown is placed on the King's head, a moment that will be marked by the Abbey bells being rung and a gun salute in nearby Horse Guards Parade.

Camilla will be crowned alongside Charles - and after the couple's long and often complicated relationship, she will now be officially described as "Queen Camilla".

The ceremony will emphasise diversity and inclusion, with more multi-faith elements than any previous coronation, with contributions from Jewish, Muslim, Buddhist and Sikh representatives.

A Bible lesson will be read by Prime Minister Rishi Sunak, who is Hindu, and music will be sung in Welsh and Scottish and Irish Gaelic.