King Charles and Queen Camilla also offered their condolences for Thomas' untimely death.
Thomas Kingston, Lady Gabriella Windsor's husband, died suddenly at the age of 45.
On Tuesday, Lady Gabriella Kingston, daughter of Prince and Princess Michael of Kent, issued a statement.
“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 illuminated the lives of all who knew him,” he said.
The statement continued: “His death has been a huge shock to the entire family and we ask that you respect our privacy as we mourn his passing.”
King Charles and Queen Camilla also expressed their condolences through a Buckingham Palace spokesperson.
“The King and Queen have been informed of Thomas' death and join Prince and Princess Michael of Kent and all those who knew him in mourning a much-loved member of the family,” the spokesperson said.
They continued: “In particular, Their Majesties send their deepest thoughts and prayers to Gabriella and the entire Kingston family.”
Thomas' cause of death has not yet been determined.
