For his final solo royal engagement, hailed as "historic", Prince Philip met with Royal Marines who had completed a 1,664-mile charity trek.
"Prince Philip, whom the Queen described as her "strength and stay" during her record-breaking reign, passed away XXXXXXX", it continued.
Philip and the Queen married in 1947, and as royal duties became more demanding, he was forced to give up a successful active military career that included serving in the Royal Navy throughout World War II.
The Queen's Consort announced in May he would be retiring from royal engagements, a decision which was fully supported by the Queen and was not medically related.
Upon his retirement in August 2017, Prince Philip has served as patron or president to some 800 organizations.
The event marked the end of the 1664 Global Challenge, which recognises 1664, the year the Royal Marines were founded, and has seen marines push themselves to the limit with a series of physical exploits in aid of the Royal Marines Charity.
Now, a few weeks after celebrating his 96th birthday, the Duke of Edinburgh will today fulfil his final royal appointment before retreating from the limelight of a lifetime spent in public service.
The Duke has also made 637 solo overseas visits, and by Wednesday, he will have delivered 5,496 speeches during his time as the longest-serving consort in British history.
In May The Sun newspaper also mistakenly published a story suggesting Prince Philip, who has suffered poor health in recent years, had died.
The couple are set to mark their 70th or platinum wedding anniversary in November this year.
He may, however, "still choose to attend certain public events from time to time", according to a statement from the Palace.
They have four children and eight grandchildren.