The Duke of Edinburgh - the longest serving consort in British history - is celebrating his 98th birthday.
Buckingham Palace, Kensington Palace, Clarence House and the Duke of York’s official Twitter account marked the occasion by sending birthday wishes to the royal patriarch.
Clarence House posted an image of a two-year-old Prince Charles holding his father’s hand after greeting him following his return home from a trip to Malta in 1951.
Prince Philip, who has been married to the Queen for more than 71 years, is edging closer to his milestone 100th birthday in 2021.
He was spotted in good form last month, laughing and joking with other members of the royal family at Lady Gabriella Windsor’s wedding.
Gun salutes will be fired in his honour by The King’s Troop Royal Horse Artillery in London’s Hyde Park at noon, as the British Army put the final preparations in place.
"Horses fed and exercised, uniforms prepared boots and Guns polished to a mirror shine," the Army said, also sending the duke congratulations via Twitter.
It added: "This is the last anniversary Salute till late Autumn so we are determined to make it a good one."
While the Queen had a busy set of engagements last week, entertaining US President Donald Trump and his wife Melania, commemorating the 75th anniversary of D-Day, and attending the Trooping the Colour celebrations, Philip will have been enjoying his time away from the limelight.
As expected, the duke, who retired from public duties in 2017 after decades of royal service, did not take part in the official events as part of the US state visit and did not meet Mr Trump behind the scenes.
He was left a personalised Air Force One jacket as a gift from Mr Trump and the First Lady.
Philip mostly stays at Wood Farm on the Sandringham estate in Norfolk, where he busies himself by reading, painting, meeting friends and staying active.
He still enjoys carriage-driving and was seen at the reins at the Windsor Horse Show in May.
The Queen and Philip recently welcomed a new great-grandchild - their eighth - with the birth of the Duke and Duchess of Sussex’s son, Archie Mountbatten-Windsor.
Philip, alongside the monarch, Harry, Meghan and the duchess’s mother, Doria Ragland, appeared in a family photograph with the latest addition to the Windsor family when Archie was only two days old.
Other family celebrations over the past year have included the wedding of the Queen and the duke’s granddaughter, Princess Eugenie, to Jack Brooksbank in October, and the Prince of Wales’s 70th birthday in November.
The duke made a rare appearance at a royal engagement early in May, joining the Queen and broadcaster Sir David Attenborough at a luncheon for Order of Merit members at Windsor Castle.
In April, he became the third oldest royal in British history overtaking Princess Alice, Countess of Athlone who was 97 years and 10 months when she died in 1981.
The duke had a dramatic start to 2019 when he was involved in a serious car crash.
The Land Rover Freelander he was driving flipped over after being hit by another vehicle carrying two women and a baby near the Sandringham estate in January.
The duke, who was miraculously unhurt, had to be rescued through the window by a passing motorist.
Philip faced criticism for taking too long to contact the occupants of the other car and for being seen driving without his seat belt in the days that followed.
Passenger Emma Fairweather, who broke her wrist, called for Philip to be prosecuted if he was found to be at fault.
The duke later apologised for his part in the incident and voluntarily surrendered his licence, with the Crown Prosecution Service saying he would face no further action.
He is still legally allowed to drive around private royal estates and has been seen doing so in the grounds of Windsor Castle.
Prince Philip of Greece and Denmark was born on the island of Corfu on June 10 1921 to Prince Andrew of Greece and Princess Alice of Battenberg.
His early years were marked by upheaval after the family went into exile following a military coup in Greece which overthrew Philip’s uncle, King Constantine I.
He moved to England to stay with relatives and study at Cheam Prep School in 1928, before spending a year at Salem School in south Germany, then finally enrolling at Gordonstoun School in Morayshire.
Philip went on to join the Royal Navy and, while a cadet, he caught the eye of a 13-year-old Princess Elizabeth.
He served with distinction during the Second World War and his friendship with the princess grew into love.
They married two years after the end of the war.
Within five years, George VI had died and Princess Elizabeth had become Queen.
The duke, who is known for his no-nonsense approach and acerbic wit, is the longest-serving consort in British history and also the oldest serving partner of a reigning monarch.