"RIP Her Majesty Queen Elizabeth II," the Sept. 9 post read. "We are deeply saddened by the death of Her Majesty The Queen. For over 70 years she dedicated her life to service for the people of the United Kingdom and the Commonwealth."
The message continued, "We offer our heartfelt sympathy to The Royal Family at this time of great sadness."
Prior to her passing, Buckingham Palace announced in a statement on Sept. 8 that doctors were "concerned" with the Queen's health. At the time, they noted that they recommended she "remain under medical supervision."
"The death of my beloved Mother, Her Majesty The Queen, is a moment of the greatest sadness for me and all members of my family," King Charles III said in a statement shared by Buckingham Palace on Sept. 8. "We mourn profoundly the passing of a cherished Sovereign and a much-loved Mother."
He added, "I know her loss will be deeply felt throughout the country, the Realms and the Commonwealth, and by countless people around the world."