The Duke has been hospitalised numerous times over the past few years, including in 2018, Prince Harry and Meghan Markle's royal wedding was notably rushed along to ensure Harry's grandfather would be well enough to attend.
Prince Philip's Life
The duke was born Philip Mountbatten to Prince Andrew of Greece and Denmark and Princess Alice of Battenberg on June 10, 1921 on the Greek island of Corfu.
He was one of five children: Princess Cecilie of Greece and Denmark, Princess Margarita of Greece and Denmark, Princess Sophie of Greece and Denmark, Princess Theodora of Greece and Denmark.
The royal was educated in Paris, then moved to the U.K. and stayed at Kensington Palace with his uncle, George Mountbatten, later attending school in Germany, which was owned by his brother-in-law, before moving on to another school in Scotland.
Sadly, in 1937 his sister and her family were killed in an air crash, which led him to join the Royal Navy, where he worked his way up to second-in-command of a ship during the Invasion of Sicily, and at just 21 and he served in the Second World War.
Philip and Queen Elizabeth II met when she was just 13, and got engaged and wed the same year at Westminster Abbey, the same venue their grandchild Prince William would wed now-wife, Kate Middleton.
The royal couple went on to live in Malta for the next few years, where they had their first son, Prince Charles in 1949, and welcomed their first and only daughter, Princess Anne, in 1950.
In 1953, Princess Elizabeth became Queen Elizabeth at age 25 after her father died and Prince Philip has been by her side throughout her reign.
Prince Andrew was their third child who was born in 1960 and four years later, their last child Prince Edward was born.
Prince Philip had eight grandchildren: Prince William, Peter Phillips, Princess Beatrice of York, Lady Louise Windsor, Prince Harry, Zara Phillips, Prince Eugenie of York and James, Viscount Severn.
He is also a great-grandfather of five: Prince George, Princess Charlotte, Prince Louis and Savannah and Isla Phillips, as well as Archie Harrison, and Princess Eugenie's new arrival, a baby boy who's name is yet to be released, as well as Prince Harry and Meghan Markle's soon-to-arrive second child.
"The Royal Family join with people around the world in mourning his loss," the Twitter statement continues. "Further announcements will be made in due course. Visit royal.uk to read the announcement in full."