The coronation of King Charles III will take place over three days in early May
The coronation of King Charles III will take place over three days in early May AFP

With around a month until King Charles III's coronation, plans are at an advanced stage to mark his historic accession to the throne -- Britain's first in seven decades.

Charles, 74, immediately became king when Queen Elizabeth died aged 96 last September, ending her record-breaking 70-year reign following a period of declining health.

But a British monarch's coronation traditionally takes place some months later, after national and royal mourning as well as intense preparation.

The early May coronation weekend will feature a star-studded concert, nationwide "big lunch" and volunteering initiative, as well as the traditional ceremony and royal processions.

The three days of ceremonial, celebratory and community events have been heralded by Buckingham Palace as a chance for "people to come together in celebration of the historic occasion".

It will begin with Charles' formal crowning at London's Westminster Abbey on Saturday May 6, in a tradition dating back more than 900 years.

The next day will then see a "special coronation concert" staged at Windsor Castle, west of London, to be produced and broadcast live by the BBC and featuring "global music icons and contemporary stars," the palace has said.

Also on May 7, neighbours and communities will be invited to host thousands of "coronation big lunches", billed as a "nationwide act of celebration and friendship".

The final part of coronation weekend, dubbed "the big help out", will be held on Monday May 8 -- designated a UK public holiday this year.

Organised by community forums and various faith groups, it will "highlight the positive impact volunteering has on communities across the nation".

In another sign of Charles's eagerness for a streamlined monarchy, his coronation ceremony will be shorter and less elaborate than the one staged for his late mother in 1953.

Then, proceedings lasted almost three hours, drew 8,251 official guests crammed into temporary tiers and included representatives from 129 nations and territories.

Instead, the palace confirmed Tuesday it will be inviting a mere 2,000 guests, while the service is set to last around an hour.

Alongside releasing a new photograph of Charles and Queen Consort Camilla taken last month, Buckingham Palace also unveiled the formal invitation to be dispatched "in due course".

Designed by heraldic artist and manuscript illuminator Andrew Jamieson, it features the motif of "the Green Man", an ancient figure from British folklore, "symbolic of spring and rebirth, to celebrate the new reign," the palace noted.

Set to be watched worldwide, various global dignitaries including political leaders, heads of state and other monarchs and civil society representatives will be in attendance.

The palace is yet to release a list of those invited.

Britain's royal family will obviously be well represented.

The palace also announced Tuesday that Charles' eldest grandson Prince George -- Prince William and wife Kate's nine-year-old son -- will be one of four Pages of Honour for the king.

Meanwhile, some foreign royals, including Prince Albert of Monaco and Prince Fumihito and his wife Kiko of Japan, have confirmed their attendance.

Several European leaders are expected and the United States will be represented by First Lady Jill Biden but without her husband, according to reports.

Among the members of the public invited is a teenager who has raised hundreds of thousands of pounds for a hospice by camping in his garden every night for three years.

Suspense remains around whether Prince Harry and wife Meghan will travel from their US home to be at the coronation.

The controversial California-based couple are increasingly estranged from the rest of the British monarchy, after giving a series of incendiary interviews criticising aspects of the institution.

Harry also published an autobiography earlier this year which, like a prior Netflix docuseries made with his wife, revealed deep rifts within the family.

A spokesperson for the pair confirmed last month that they have been invited, but would not say if they had agreed to attend.

Talks are taking place with the palace about their roles and over security, according to British media.

Queen Consort Camilla will also be formally crowned on May 6 -- wearing Queen Mary's Crown. More than a century old, it was commissioned by Queen Mary for her 1911 coronation alongside King George V.

Charles will wear the St Edward's Crown.

Camilla's family, through her first marriage to Andrew Parker Bowles, will also be involved, with three of her five grandchildren and a great-nephew serving as her Pages of Honour at the service.