A cause of death has been released for Queen Elizabeth II. Her death at Balmoral Castle in Scotland at age 96 ended a record-setting 70-year reign as monarch of the United Kingdom.

A funeral service for Queen Elizabeth was held Sept. 19 at centuries-old Westminster Abbey in London, with her burial taking place later that day at St. George’s Chapel near Windsor Castle. She was laid to rest next to her late husband, Prince Philip, who died last year at age 99.

Her death certificate listed the British monarch as “widowed.” It said she died of “old age” at 3:10 p.m. on Sept. 8, according to a death certificate released Thursday by the National Records of Scotland. For “occupation” of the deceased, the official form says: “Her Majesty the Queen.”

The funeral concluded a 10-day mourning period in which family members including the queen’s four children participated in coffin processions through Edinburgh and London.

Her coffin laid in state for four days at London’s Westminster Hall, with people lining up for as long as 24 hours to pay their respects ahead of the funeral.

The funeral was attended by about 2,000 people, including royals such as Prince William and Prince Harry and world leaders such as U.S. President Joe Biden.

Queen Elizabeth’s eldest child, 73-year-old King Charles III, became the British monarch following his mother’s death. He left a note on her coffin that read, “In loving and devoted memory. Charles R,” with the “R” referring to “Rex,” or “king” in Latin.

The queen was 25 years old when her monarchy began in 1952 after her father’s death. A platinum jubilee commemorating the 70th anniversary of Queen Elizabeth’s monarchy took place earlier this year.

BBC.com showed a copy of the death certificate. It said of the record: “It requires the names and occupations of parents — her father formally recorded as Albert Frederick Arthur George Windsor, whose occupation was King George VI, her mother as Elizabeth Angela Marguerite Bowes-Lyon, who was Queen Elizabeth the Queen Mother.”