The Duke and Duchess of Gloucester joined Queen Camilla, Prince William and other senior royals at Monday's Commonwealth Day service.
The royals often keep a lower profile, while still carrying out some royal duties on behalf of the royal family. Richard was the late Queen's cousin, with the pair sharing King George V as their grandfather. His father, Prince Henry, was Queen Elizabeth's uncle.
But what do you know of the Duke of Gloucester, including his family life? Here's all you need to know about Prince Richard…
About the Duke of Gloucester
Prince Richard was born on 26 August 1944 in Northampton as the youngest son of Prince Henry, Duke of Gloucester and Princess Alice, Duchess of Gloucester, and at the time of his birth, Richard was fifth in line to the throne.
As he had an older brother, Prince William of Gloucester, Richard began planning for a more civilian life, and the royal went to study architecture at Magdalene College, Cambridge, graduating with a Bachelor of Arts. Following his studies, Richard became a practicing partner at Hunt Thompson Associates.
However, on 28 August 1972, Richard's brother, William, was killed in a plane crash as he competed in the Goodyear International Air Trophy. Richard's father died two years later on 10 June 1974, at which point the royal became the Duke of Gloucester.
As of 2019, the Duke and Duchess both live at Kensington Palace, residing in the Old Stables.
How did he meet the Duchess of Gloucester?
Prince Richard met Danish-born Birgitte van Deurs while they both studied at Cambridge during the 1960s, with the Duchess pursuing a degree in languages.
Following her graduation, Birgitte began work as a secretary in the Danish embassy, and in 1972, Richard sought the late Queen's permission to marry his beloved. The engagement caused a small storm, with the New York Times running an article titled 'Queen's cousin will marry a secretary'.
The couple married on 8 July 1972, a month before his brother died, with the duo walking down the aisle at St Andrew's Church in Barnwell, Northamptonshire.
Their children
The Duke and Duchess share three children: Alexander Windsor, Earl of Ulster, Lady Davina Windsor and Lady Rose Gilman.
Alexander was born on 24 October 1974 and is the heir apparent to his father's royal titles, he currently uses the Earl of Ulster as a courtesy title. In 2002, Alexander married Claire Booth and the pair share two children, Xan, Baron Culloden, 17, and Lady Cosima Windsor, 13.
Lady Davina Windsor was born on 19 November 1977 and graduated from the University of West England with a degree in media studies. In 2004, Davina married businessman Gary Lewis, who became the first person of Māori descent to marry a royal. However, in 2018, the couple divorced with Buckingham Palace sharing the news a year later.
The former couple share two children, daughter Senna, 13, and son Tane, 11.
Lady Rose was born on 1 May 1980 and in 2008, she walked down the aisle with George Gilman, the son of property developer Peter J. I. Gilman. The pair share two children, Lyla, 13, and Rufus, 11.
None of Richard or Birgitte's children carry out royal duties, however, they are occasionally seen at royal events such as weddings.
Schedule as a working royal
Although not as high-profile as senior members of the royal family, the Duke of Gloucester still carries out dozens of royal engagements a year. The royal family's website says: "He attends national and international events in support of The King and his duties as Head of State, as well as undertaking extensive public duties and engagements every year reflecting his own interests and charities."
Architecture is still at the heart of Richard's life, despite having to give up his career, with the royal serving as president of the Society of Architect Artists.
The Duke has carried out royal visits to countries such as Malawi and the Solomon Islands, and during the late Queen's funeral in 2022, he formed part of the cortege that walked with royal's coffin from Buckingham Palace to Westminster Hall, where it laid in state for a week.
MORE: Queen Camilla steps out with the Duchess of Gloucester after returning to London with King Charles