Prince Philip has died aged 99.
He was the longest-serving British consort and dedicated more than half a century to supporting the Queen.
When an 18-year-old Philip started writing to his 13-year-old second cousin once removed, Princess Elizabeth, in 1939, little did he know what he would have to sacrifice for a life of service.
Watch: Prince Philip Funeral: Royal Procession Behind Duke's Coffin
Born into the Greek and Danish royal families, Philip attended Gordonstoun School in Scotland and the Royal Naval College at Dartmouth.
He joined the British Royal Navy in 1939 at the age of 18 and went on to serve with the Mediterranean and Pacific fleets in the Second World War.
His first sacrifice came when Philip was granted permission by King George VI to marry Elizabeth.
Before the official announcement of their engagement in July 1947, Philip abandoned his Greek and Danish royal titles as a member of the House of Schleswig-Holstein-Sonderburg-Glücksberg and adopted the surname Mountbatten.
The sudden death of George VI meant Elizabeth became monarch in 1952, forcing another sacrifice for her husband sooner than either of them may have predicted.
When Elizabeth became Queen, Philip left active military service having reached the rank of Commander, effectively giving up a promising naval career that could have seen him become First Sea Lord.
Some have speculated that he had hoped to spend longer as a military man before settling into life at the Queen's side, becoming - in his own words - "the world’s most experienced plaque unveiler".
Speaking on the couple's 70th anniversary, Buckingham Palace commentator Richard Fitzwilliam said: “Philip would have far preferred a naval career than to be in a supporting role.”
The sacrifice of his own ambitions to serve the Queen and his country was highlighted in popular Netflix series The Crown.
Series creator Peter Morgan is quoted as saying: “Philip, I think, had made the mental calculation that he would enjoy 20 years of married life before this dreadful crown business would happen.”
“He was forced to give up his career and become, as it were, her consort. And that led to all sorts of tensions, both within himself and within the marriage.”
Since then, Philip's life was spent by his wife's side.
In 2009 he became the longest-serving British consort, a title previously held by George III's consort Queen Charlotte.
Up until his retirement from public duties in the summer of 2017, at the age of 96, Philip had dedicated decades to supporting the Queen on charitable arrangements.
As well as founding The Duke of Edinburgh Award scheme in 1956, he was patron or president of some 800 organisations and on his retirement had undertaken 22,191 solo engagements and given 5,493 speeches in almost seven decades.
His devotion to his wife was evident in his retirement too, and he moved from Wood Farm, his Sandringham home, to Windsor Castle when the coronavirus pandemic hit.
They spent many months together, likely the longest time since the early days of their marriage, as they shielded to avoid the risk of COVID-19.
He even added a bonus engagement to his list, appearing at Windsor Castle for a transfer ceremony of the role of Colonel-in-Chief of The Rifles, in July 2020.
Watch: Minute's Silence Observed for Prince Philip Outside Windsor Castle