Royals at Windsor Castle for King Charles' first Order of the Garter service

King Charles III and Queen Camilla arrived for the procession through Windsor Castle together

The King has attended his first service for the Order of the Garter since being crowned.

Members of the Royal Family attended Windsor Castle for the service of the oldest order of chivalry in Britain.

The event marked the official installation of two new members to the service.

Former Labour minister Catherine Ashton was made Lady Companion, while Chris Patten, the final governor of Hong Kong, became a Knight Companion.

Thousands of members of the public attended the event after winning ballot tickets

Thousands of members of the public gathered inside the castle grounds to see the procession arrive at St George's Chapel.

Members of the Order in attendance included former prime ministers Sir Tony Blair and Sir John Major, as well as the Prince and Princess of Wales and the Duke of Edinburgh.

Queen Camilla arrived with King Charles for the ceremony, which was attended by 800 guests inside the chapel and 2,900 members of the public who had won ballot tickets.

The Duke of York, who is also a member of the Order, did not attend.

The Prince and Princess of Wales were also seen attending the service in St George's Chapel

Two other members of the Order, Lord Shuttleworth and Lord Luce, were named in the order of service but were unable to attend.

After the service, a procession of four Ascot Landau coaches ferried away members of the royal family who waved to the crowds as they went past.

The Duke of Edinburgh and Princess Anne, both members of the Order, were also in attendance

The Order of the Garter was established by King Edward III nearly 700 years ago.

It comprises 24 members, including the King and Queen, several members of the royal family and 18 knights or ladies.

The Royal website states: "Knights of the Garter are chosen personally by the Sovereign to honour those who have held public office, who have contributed in a particular way to national life or who have served the Sovereign personally."

Former Labour minister, Catherine Ashton (left) was made Lady Companion, while Chris Patten (right) the final governor of Hong Kong, became a Knight Companion