For the world’s most powerful, there can be no fixture quite as rare, glittering and sought after as a British coronation.
There has not been one for seven decades and leaders and their retinues are flying in to take part.
For Britain, it is a chance to show off its best assets and exude and exert as much soft power as is diplomatically possible at the start of the Carolean era.
Convention has for centuries dictated that other crowned royals do not attend British coronations. Not this time.
At least four kings and queens and a clutch of princes and princesses are on their way. There will be 90 heads of state in attendance.
US President Joe Biden is following convention and not coming, represented by his wife, the first lady, instead. But most presidents or prime ministers that you would expect will be there.
The Foreign Commonwealth and Development Office (FCDO) says 450 foreign dignitaries will be in Westminster Abbey in total – that is about a quarter of the congregation, with 200 nations, realms and Commonwealth countries being represented.
Seating them all will require strict adherence to protocol to avoid causing offence.
In front rows will be foreign royals and representatives of the realms, those 14 countries that still regard the king as head of state.
Behind them, representatives of overseas territories, then representatives from other commonwealth nations with their own heads of state. Behind them, other guests will be seated in strict alphabetical order.
In all, the FCDO will be hosting 220 foreign delegations this weekend.
The list of countries not to receive an embossed invitation from Buckingham Palace is short and predictable. Afghanistan, Belarus, Myanmar, Russia, Syria, Iran and Venezuela. North Korea has been invited but only at ambassadorial level. Nicaragua likewise.
But China has been asked. And that is causing considerable controversy because the man Beijing is sending is widely regarded as the oppressor of Hong Kong. China’s President Xi Jinping has turned down the invite and is sending his vice president instead.
Han Zheng is the Chinese official who did most to rip up the British-Chinese agreement over the former colony, order a brutal crackdown on protests and send hundreds to jail.
The Committee for Freedom in Hong Kong Foundation told Sky News: “It is pretty disgraceful that the architect of Hong Kong’s demise has been invited to the coronation of King Charles III while other partners with whom the UK has an excellent relationship with, such as Taiwan, have been excluded.
“Who calls the shots in Britain, is it Beijing or our prime minister? Why are we kowtowing to Beijing for the guest list to our own coronation?”
Conservative MP Iain Duncan Smith, who has been sanctioned by the Chinese government, told Sky News: “Han Zheng is primarily responsible for the crack down on democracy campaigners in Hong Kong under the brutal new national security law. Many are British passport holders, particularly Jimmy Lai, journalist and owner of Apple Daily [the Hong Kong pro-democracy paper].
“The architect of this brutal policy in Hong Kong will rub shoulders with the British PM and the King whilst Jimmy Lai and others have lost their freedom.”
Undeterred by the controversy, Britain’s Foreign Secretary James Cleverly will be meeting Han Zheng ahead of the coronation.
His officials say he will be discussing “points of criticism” with the vice president. Among them will be China’s treatment of the Uyghur minority in Xinjiang province and failure to abide by commitments in Hong Kong.
But former Hong Kong governor Chris Patten says Han’s attendance at the coronation shows that China does not give “two hoots” about the UK.
Ministers are exploiting the presence of a host of foreign dignitaries in London for less controversial meetings on the sidelines of the event.
The government will be hoping the coronation will be a powerful projection of Britain’s soft power – not least the attendance of globally-known celebrities, from Joanna Lumley and the Beckhams to Mr Bean (aka Rowan Atkinson).