Queen Elizabeth II, the longest-reigning monarch in British and Commonwealth history, died on Thursday. Buckingham Palace confirmed the news. She was 96.

"The Queen died peacefully at Balmoral this afternoon," the statement read. "The King and the Queen Consort will remain at Balmoral this evening and will return to London tomorrow."

The news comes just hours after Buckingham Palace released a statement noting concern for the royal's health. In a rare comment, the palace confirmed on Sept. 8 that the Queen would remain under medical supervision at her home in Balmoral. Following the news, the Queen's children and grandchildren traveled to be by her side, including her son and heir, Prince Charles, as well as Prince William and Prince Harry.

Born to King George VI and Queen Elizabeth on April 21, 1926, Elizabeth II was not predestined to take the throne, and she spent her first decade in a relatively minor role in the royal family. This changed with the death of her grandfather King George V in 1936. The next in the line of royal succession was her uncle, Edward VIII, who abdicated the throne less than a year after his reign so he could marry American socialite Wallis Simpson. His brother (and Elizabeth's father) Albert, who later took the name George VI, became king, which paved the way to Elizabeth becoming heir presumptive, as she had no brothers.

While she remained primarily out of the public eye in her preteen years, she began to assert a more active role during World War II. She made her first radio appearance at age 14 in 1940 during BBC's Children's Hour to address youth who were evacuated during Germany's blitz bombing campaign. She became the first female member of the royal family to become a full-time active member of the British Armed Forces in 1945, when she joined the Auxiliary Territorial Service and trained as a truck driver and mechanic. Five months later, she earned the rank of honorary junior commander.