Prince William steps out solo for wedding of his and Prince Harry's close friend

Prince William on Friday celebrated the marriage of one of his and Prince Harry's closest friends.

William served as an usher at the wedding of Hugh Grosvenor, the Duke of Westminster, and Olivia Henson. The couple wed at Chester Cathedral in Chester, England, about four hours outside of London.

William was seen mingling with guests at the wedding, which he attended solo, without his wife Kate, the Princess of Wales, who has stayed out of the public eye since announcing in March that she had been diagnosed with cancer.

William's younger brother Harry, who now lives in California with his wife Meghan, the Duchess of Sussex, and their two children, also did not attend the wedding.

Both William and Harry chose Grosvenor, their lifelong friend, to be the godfather to each of their respective eldest children, Princes George and Archie.

Grosvenor is also the godson of King Charles III, William and Harry's father.

Neither Charles nor his wife Queen Camilla attended the wedding on Friday.

Charles, like his daughter-in-law Kate, was also diagnosed with cancer this year.

The types of cancer with which Charles and Kate were diagnosed have not been disclosed.

As he did Friday at Grosvenor's wedding, William has been attending events solo in recent months, in the wake of both his wife's and father's diagnoses.

On Thursday, William stood in for Charles alongside heads of state at a ceremony to mark the 80th anniversary of D-Day.