Thomas Kingston, husband of Lady Windsor Gabrielle, led a life both in finance and in service to the UK.

The 45-year-old British financier died yesterday, a shock announcement on behalf of his family said. The statement, made on behalf of his wife Lady Gabriella Kingston, and his parents Mr Martin and Mrs Jill Kingston, as well as his sisters 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."

Known professionally as a financier, Mr Kingston's expertise lay in frontier market investment.

He was the director of Devonport Capital, and was once described as "the most eligible man in London".

He even previously dated Pippa Middleton in 2011.

Mr Kingston worked in the Diplomatic Missions Unit of the United Kingdom's Foreign Office, and for almost three years worked in Baghdad as a project officer for the Iraqi Institute of Peace.

During this time his job was to mediate conflicts in Iraq, including helping to negotiate the release of hostages.

He then went on to work as Managing Director at Voltan Capital Management - a role with a salary estimated to be around £150,000.

The precise net worth of Thomas Kingston remains undisclosed. Due to his career in finance, speculators suggest he may have amassed considerable wealth - but the exact figure is not currently known.

Thomas' wife, Lady Gabriella Windsor, is the daughter of Prince and Princess Michael of Kent.

The late Queen and Prince Michael were first cousins through their fathers.

A Palace spokesperson said after Mr Kingston's death: "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."