Thomas Kingston, the husband of Prince and Princess Michael of Kent’s daughter Lady Gabriella Kingston, has died suddenly at the age of 45, Buckingham Palace has announced.

Lady Gabriella paid tribute to her financier husband in a joint statement with his family, describing him as an “exceptional man who lit up the lives of all who knew him”.

They described his death as a “great shock to the whole family”.

The King and Queen sent their “most heartfelt thoughts and prayers” to Lady Gabriella, who is known as Ella, and Mr Kingston’s parents and siblings.

Mr Kingston, known as Tom, was found dead at an address in the Cotswolds in Gloucestershire on Sunday evening, and emergency services were called to the scene shortly after 6pm.

An inquest will be held to establish the cause of death, but there are no suspicious circumstances and no other parties involved.

A statement released on behalf of Lady Gabriella Kingston, Mr Martin and Mrs Jill Kingston, Mrs Joanna Connolly and Mrs Emma Murray, said: “It is with the deepest sorrow that we announce the death of Thomas Kingston, our beloved husband, son and brother.

“Tom was an exceptional man who lit up the lives of all who knew him. His death has come as a great shock to the whole family and we ask you to respect our privacy as we mourn his passing.”

Lady Gabriella released a personal photo she took of her husband, showing him smiling and dressed in a casual pink shirt as he stood near a stretch of water in the sunshine.

The couple married at St George’s Chapel, Windsor Castle, in 2019 with Queen Elizabeth II and her husband, the late Duke of Edinburgh, among the guests.

A Buckingham Palace spokesperson said: “The King and the Queen have been informed of Thomas’s death and join Prince and Princess Michael of Kent and all those who knew him in grieving a much-loved member of the family.

“In particular, Their Majesties send their most heartfelt thoughts and prayers to Gabriella and to all the Kingston family.”

Lady Gabriella is the King’s second cousin. They are both great-grandchildren of King George V.

Mr Kingston was a director of Devonport Capital, which specialises in providing finance for companies in “frontier economies”.

The Bristol University graduate had also worked in Baghdad, Iraq, working to procure the release of hostages after joining the Diplomatic Missions Unit of the Foreign Office.

He was a close friend of Pippa Matthews – the Princess of Wales’s sister – and the pair were said to have dated in 2011.

Lady Gabriella, who has worked as an arts and travel director for a brand company, is a writer and contributing editor.

She is also a singer-songwriter and released two bossa-nova inspired tracks in 2020 to raise money for charity.

Although Lady Gabriella is not a working member of the royal family, she and Mr Kingston’s family are being supported by the Royal Household through this difficult time.

No funeral plans have been released so far.

Lady Gabriella’s parents Prince and Princess Michael of Kent attended the service for the late King Constantine II of Greece on Tuesday in St George’s Chapel, Windsor Castle.

Constantine was Lady Gabriella’s godfather and attended her wedding.

The Prince of Wales, also a godchild of the former Greek monarch, pulled out of attending at the last minute, but his absence was due to a personal matter and was understood not to be connected to news of Mr Kingston’s death.

Gloucestershire Police said in a statement: “We were called by the ambulance service at 6.25pm on Sunday with a report of the death of a 45-year-old man at an address in the Cotswolds.

“The death is not being treated as suspicious and a file will be prepared for the coroner.”