ENGLAND - Prince Philip, husband to Britain's Queen Elizabeth II, has died at 99 years of age, Buckingham Palace announced Friday. 

In a statement, the palace said: "It is with deep sorrow that Her Majesty The Queen announces the death of her beloved husband, His Royal Highness The Prince Philip, Duke of Edinburgh. His Royal Highness passed away peacefully this morning at Windsor Castle. Further announcements will be made in due course. The Royal Family join with people around the world in mourning his loss."

It is with deep sorrow that Her Majesty The Queen has announced the death of her beloved husband, His Royal Highness The Prince Philip, Duke of Edinburgh.

His Royal Highness passed away peacefully this morning at Windsor Castle. pic.twitter.com/XOIDQqlFPn

— The Royal Family (@RoyalFamily) April 9, 2021

After falling ill on February 17, the duke became a patient at London's King Edward VII Hospital.

The palace later confirmed that he was being treated for an infection and on March 1, he was transferred to St. Bartholomew's Hospital, also in London, where doctors continued to treat the infection as well as undertake testing for a pre-existing heart condition.

The duke underwent heart surgery and was released from the hospital in mid-March.

Philip, whose official title was Duke of Edinburgh, served as the longest-serving British consort.

He married the then Princess Elizabeth in 1947 and throughout his seven decades of service, often accompanied the Queen on royal engagements, in addition to conducting thousands of his own solo appearances.

He once called himself "the world's most experienced plaque unveiler," while the Queen praised him as her "constant strength and guide."

Prince Philip and Elizabeth had four children: Charles, Anne, Andrew and Edward.