King Charles III on Tuesday welcomed South African President Cyril Ramaphosa to London for a milestone first state visit of his reign.
Gun salutes were fired across London as Charles and Queen Consort Camilla were joined by heir to the throne Prince William and his wife Catherine to greet Ramaphosa for a ceremonial welcome at Horse Guards Parade.
The monarch and Ramaphosa, both dressed in dark overcoats against the November chill, inspected the guard of honour together.
The parties then travelled to Buckingham Palace in a carriage procession escorted by mounted soldiers from the Household Cavalry.
The route along The Mall was decorated with the British and South African flags with the band of the Scots Guards playing the national anthems of both countries as the king and his guest arrived at the palace.
The two-day visit sees Charles finally presiding over proceedings after decades playing a supporting role to his mother Queen Elizabeth II, who died in September.
For Ramaphosa, a protege of anti-apartheid icon Nelson Mandela, however, it comes amid political difficulties and a threat of impeachment at home.
In the last state visit of Elizabeth's record-breaking 70-year reign, the queen hosted US president Donald Trump and his wife Melania in June 2019.
Later in the day, Ramaphosa will visit parliament for an address to both the upper and lower houses.
A tour of Westminster Abbey will include the memorial stone for Mandela, who served as president of South Africa between 1994 and 1999.
In the evening, Ramaphosa will attend a state banquet at Buckingham Palace.
Ramaphosa is also due to visit Downing Street for talks with Prime Minister Rishi Sunak.
At the start of the visit, the UK and South Africa governments announced the launch of the next phase of the UK-South Africa Infrastructure Partnership.
"South Africa is already the UK's biggest trading partner on the continent, and we have ambitious plans to turbocharge infrastructure investment and economic growth together," Sunak said.
Trade with South Africa, the continent's second biggest economy, is worth £10.7 billion ($12.7 billion) a year.
Foreign Secretary James Cleverly said the choice of Ramaphosa for Charles's first state visit was a sign of the UK's "enduring commitment" to Africa, even as it eyes new partners in Asia post-Brexit.
But he added: "It's important... that we also show that it's not going to be at the expense of the incredibly important partnerships we have through the Commonwealth, through international fora, as well as the bilateral relationship (with South Africa)."
As well as trade, climate change and Charles's vision for the Commonwealth are also expected to be discussed during the visit.
But political problems in South Africa threaten to cast a shadow over the ceremonial pomp and splendour of the state visit.
Ramaphosa is at risk of impeachment for allegedly covering up a crime, accused of concealing a multi-million-dollar cash theft.
He faces an accusation that he failed to report a heist at his luxury cattle farmhouse in which robbers took four million dollars in cash, and instead organised for the robbers to be kidnapped and bribed into silence.
He has faced calls to resign and the deeply divided ruling African National Congress (ANC) is due to hold a vote on its leadership in December.
The president has acknowledged a burglary but denies kidnapping and bribery, saying he reported the break-in to the police.
South African lawmakers will discuss next month the findings of a special panel tasked with establishing whether Ramaphosa should face impeachment.