By Sean Coughlan, royal correspondent, and Sean Seddon
BBC News
The Prince of Wales has carried out his first public duty since his wife’s abdominal surgery and father’s cancer diagnosis.
Prince William performed an investiture ceremony at Windsor Castle on Wednesday and will appear at a charity event this evening.
He is expected to take on extra engagements in the King’s absence.
On Wednesday, No 10 said the prime minister’s weekly audience with the King would take place over the phone.
Downing Street does not usually comment on the meetings but said it agreed with the Palace “in this specific instance to confirm that they will be speaking on the phone later”.
The King has travelled to Sandringham in Norfolk with the Queen. His “regular treatments” for an unspecified cancer began on Monday.
Prince William’s return to public duties follows a three-week absence which began after Catherine, the Princess of Wales, underwent surgery.
While Buckingham Palace has stressed the King will continue to perform his formal constitutional functions, Prince William will stand in for him at some events.
The Princess of Wales is continuing her recovery at home after spending a fortnight in hospital.
According to palace sources, Prince William has until now been focusing on being at the side of his wife and children, rather than carrying out public engagements.
But with an “unwavering commitment to duty and service”, he is now returning to his public role with the investitures and an air ambulance fundraising event later on Wednesday.
The investitures – where people receive honours in person from a member of the Royal Family – were said toreflect his support for people playing an important role in their communities.
Among those he met were Suzie Hutchinson, who runs Little Heart Matters, a charity for people with a single ventricle heart condition – or half a working heart.
Also among those being honoured were John Broadfoot, founder of SOS Kit Aid, whose charity sends second-hand sports kit to disadvantaged people around the world.
The prince was also pictured chatting with Ellen Convery – formerly known as Ellen White – who played over 100 games for the England women’s football team.
King Charles’s cancer diagnosis
He was pictured sitting alongside the Queen in the back of a car leaving Clarence House in London as they travelled to their home in Sandringham, Norfolk.
Earlier in the day, the King spent 45 minutes with the Duke of Sussex, who flew from LA after being informed of the cancer diagnosis over the phone by his father.