The old bunting’s out, and the new King’s in.

Overnight, King Charles III was crowned in London’s Westminster Abbey in a formal religious ceremony steeped in thousand-year-old traditions, but with modern touches and more inclusion.

The ceremony means the longtime Crown Prince is now formally King of the United Kingdom and 14 Commonwealth realms, including New Zealand, as well as being head of the 56-member Commonwealth of Nations.

New Zealand Prime Minister Chris Hipkins was among 2000 invited guests inside the Abbey in a star-studded ceremony which included actresses Dame Joanna Lumley, Dame Judi Dench, Emma Thompson and singers Katy Perry and Lionel Richie.

A smiling Prince Harry, the King’s US-based son who quit his Royal duties in 2020, walked into the Abbey behind the disgraced Prince Andrew, following his cousins Princess Beatrice and Princess Eugenie. The palace has said Harry’s wife Meghan would remain in the US with the couple’s two children.

Britain's Prince Harry, Duke of Sussex arrives to attend Britain's King Charles III and Camilla, the Queen Consort, coronation ceremony at Westminster Abbey, London, Saturday, May 6, 2023. (Toby Melville, Pool via AP)

While Harry was relegated to the third row, Prince William and wife Catherine, Princess of Wales, and their two youngest children, Charlotte, 8, and Louis, 5, sat in the front row, alongside Charles’ brother Prince Edward and his wife Sophie.

Their eldest son, 9-year-old future King, Prince George, was one of eight pages who had a starring role in the ceremony, carrying state robes.

Prince George attends the coronation ceremony of King Charles III and Queen Consort in London, Saturday, May 6, 2023. (Andy Stenning/Pool photo via AP)

The children melted hearts with Charlotte protectively holding her little brother’s hand. She wore a scaled-down version of her mother’s Alexander McQueen gown, and a Jess Collett x Alexander McQueen headpiece.

Britain's Prince William and Kate, Princess of Wales, followed by Princess Charlotte and Prince Louis, arrive at the coronation of King Charles III at Westminster Abbey, London, Saturday, May 6, 2023. (Phil Noble/Pool Photo via AP)

From left, 1st row, Britain's Prince William, Princess Charlotte, Prince Louis, Kate, Princess of Wales and the Prince Edward Duke of Edinburgh at the coronation ceremony of King Charles III in Westminster Abbey, London, Saturday May 6, 2023. (Yui Mok, Pool via AP)

The pageantry began on a cool, drizzly Saturday morning (10pm NZT), with the King and the Queen Consort, Camilla, travelling in The King’s Procession past cheering, flag-waving crowds from Buckingham Palace to Westminister Abbey in the Diamond Jubilee State Coach.

Hipkins, wearing a new suit and a loaned kākahu (Māori cloak) created by Gerry Williamson of Ngāti Rānana London Māori Club, said the Coronation would be “an extraordinary event”.

Prime Minister Chris Hipkins on his way to King Charles Coronation at Westminster Abbey in London. 8 May 2023. Photo / Video Screengrab

Dame Cindy Kiro Governor General New Zealand and Prime Minister Chris Hipkins and guests arrive prior to the coronation ceremony of Britain's King Charles III in London Saturday, May 6, 2023. (AP Photo/Alessandra Tarantino)

Wearing a long cream and maroon state robe, the King entered the abbey alongside his wife of 18 years - now to be known as Queen Camilla.

Upon arrival the King was presented to those in attendance by Archbishop of Canterbury Justin Welby, a shout of “God save the King” echoing through the almost-800-year-old abbey.

The only part of the hour-long ceremony required by law was King Charles’ swearing to uphold the law and Church of England.

The King also took a second oath - the Accession Declaration Oath - stating he was a “faithful Protestant”.

The Procession of King Charles travels to Westminster Abbey for the coronation of King Charles III in London, Saturday, May 6, 2023. (Adam Gerrard/Pool Photo via AP)

The BBC reported that while there were debates about the King’s oath stating his specific role as upholder of the “Protestant succession to the throne”, soon after the pledge the choir sang a piece in Latin by William Byrd, from a setting of the mass used by 16th Century Catholics who had opposed the doctrine of the Church of England.

There were also representatives of Muslim, Jewish, Sikh and Buddhist communities, and British Prime Minister Rishi Sunak, a Hindu, gave a Bible reading. Women bishops were also taking part for the first time and several languages, including Greek - a nod Prince Philip’s birthplace.

They were there to crown a King, said Welby, the Archbishop of Canterbury, in his sermon.

“And we crown a king to serve ... service is love in action.”

Britain's King Charles III during the coronation ceremony in Westminster Abbey, London, Saturday May 6, 2023. (Yui Mok, Pool via AP)

An anointing screen is erected for Britain's King Charles III during his coronation ceremony in Westminster Abbey, London, Saturday May 6, 2023. (Yui Mok, Pool via AP)

In the most solemn part of the ceremony the King was disrobed and, wearing a plain white linen robe and as the choir sang Handel’s Coronation Anthem No. 1 (Zadok the Priest), annointed with holy oil using a gold ampulla and a spoon made from silver gilt and pearls dating from the 12th century.

The annointment took place behind a screen made from New Zealand and Australian wool and portraying a tree representing the Commonwealth countries.

For the Investiture the King dressed in a glittering, embroidered robe made of gold silk, called the Supertunica, under the Golden Imperial Mantle, which was first made for King George IV in 1821.

He was presented with the Jewelled Sword of the Offering, the Imperial Mantle, Orb, Coronation ring and sceptres, one containing the world’s largest colourless cut diamond.

Heir Prince William gave his father a garment known as the Stole Royal.

The final act was the placing of the more than 360-year-old 2.2kg St Edward’s Crown, made of solid gold and encrusted with 444 gemstones, on the King’s head - as it was for his mother, Queen Elizabeth, in 1953.

King Charles III is crowned with St Edward's Crown by The Archbishop of Canterbury the Most Reverend Justin Welby, during his coronation ceremony in Westminster Abbey, London, Saturday May 6, 2023. (Yui Mok, Pool via AP)

Britain's King Charles III is crowned with St Edward's Crown by The Archbishop of Canterbury Justin Welby during his coronation ceremony in Westminster Abbey, London, Saturday, May 6, 2023. (Aaron Chown/Pool Photo via AP)

Britain's King Charles III wears St Edward's Crown during his coronation ceremony in Westminster Abbey, London, Saturday May 6, 2023. (Yui Mok, Pool via AP)

Not all heads are made for Crowns, but all devices may be with a St Edward’s Crown emoji created for the first Coronation in the digital age.

A smaller ceremony for Queen Camilla followed before the couple left in the 4000 kilogram Gold State Coach - used at every Coronation since 1831.

The much larger scale return was to include Armed Forces from across the Commonwealth and the British Overseas Territories, and was to be followed by the traditional balcony wave by the King and his family.

Britain's King Charles III and Camilla, the Queen Consort, are on the way to the coronation ceremony in London Saturday, May 6, 2023. (AP Photo/Jon Super, Pool)

Newly crowned King Charles III and Queen Camilla have emerged from Westminster Abbey for a grand procession returning to Buckingham Palace after his coronation.

People gather on The Mall, in London, ahead of the coronation ceremony of Britain's King Charles III in Westminster Abbey, Saturday, May 6, 2023. (AP Photo/Andreea Alexandru)

The Coronation is expected to cost around £100m (about NZ $200m ). By contrast, Queen Elizabeth’s 1953 coronation cost about £1.57m - which is equivalent to £35.52m in 2023 - almost NZ $71m.

However, a higher level of security is thought to be responsible for the increased cost.

Earlier, hoards of anti-monarchy protestors had threatened to delay the event, with police and guards forced to move them on at The Mall.

However, royal fans far outweighed the noise from protestors as crowds began singing and shouting “God save the king!”, Herald lifestyle editor Jenni Mortimer said.

“When the incredible moment came and the horses and guards announced the arrival of the King and Queen in the carriage, phones raised in the air as far as the eye could see and the screams amplified.”

A woman holds a little boy wearing a crown before the start of Britain's King Charles III coronation ceremony on The Mall, in London, England, Saturday, May 6, 2023. (AP Photo/ Andreea Alexandru )

King Charles reign began in September, the role of a lifetime the newly-crowned King had waited almost a lifetime to begin.

Seventy-four-and-a-half years ago, it all lay ahead for the firstborn son of then-Princess Elizabeth, all 3.3 kilograms (7lb 6oz) of him as his arrival at London’s Buckingham Palace on November 14 1948 lifted spirits in a post-war nation.

Prince Charles with his Aunt, Princess Margaret (r) and his Grandmother, Elizabeth the Queen Mother, at the 1953 Coronation of his mother, Queen Elizabeth II. Photo / Getty

His mother Elizabeth, who would go on to be the longest reigning Queen of the United Kingdom and multiple realms before her death age 96 in September last year, was the eldest daughter of then-King George VI - who 12 years earlier had found himself an unexpected monarch when elder brother King Edward VIII abdicated.

- Cherie Howie and Jenni Mortimer, NZH