The Duke of Edinburgh celebrates his 93rd birthday today.
Philip will spend part of the day at a Buckingham Palace garden party, when 8,000 invited guests will descend on the royal residence to take tea in the 40 acre gardens.
He will be joined on the Palace terrace by the Queen, the Duchess of Cambridge, the Duke of York, Princess Eugenie, the Princess Royal and other members of the royal family for the playing of the National Anthem by a military band before the royals circulate through the lanes of guests on their way to the Royal tea tent.
A 41-gun salute will be fired by the King's Troop Royal Horse Artillery from London's Hyde Park at noon in celebration.
An hour later the Honourable Artillery Company will fire a 62-gun salute from Gun Wharf at the Tower of London, with the extra guns a tribute from the citizens of the City of London.
The Duke, who shows no signs of slowing down amid a packed programme of engagements, has a busy run of events this week despite having just returned from a high profile three day state visit to France to mark the 70th anniversary of the D-Day landings.
Yesterday evening, he joined the Queen at a Palace reception in honour of the UK's technology sector.
The rest of the week remains hectic including a solo overseas day trip to Germany on Thursday to present campaign medals in Fallingbostel in his role as Royal Colonel, of The Highlanders, Fourth Battalion, The Royal Regiment of Scotland.
On Wednesday, Philip, as founder of The Duke of Edinburgh's International Award Association, will hold the World Fellowship 27th anniversary dinner at Windsor Castle, while on Friday he visits Hindleap Warren Outdoor Education Centre in Sussex and then chairs the Senior Colonel's Conference at Buckingham Palace.
The demanding diary rounds off on Saturday when the royals are out in force for Trooping the Colour - the Queen's official birthday parade.
But next week, the Queen, who turned 88 in April, and the Duke will also take part in the annual Order of the Garter service at St George's Chapel, Windsor Castle. The next day sees the start of Royal Ascot week, which the monarch and Philip usually attend.
Last week, the royal couple travelled by Eurostar to France for a three day trip, which saw them pay their respect to the nation's war dead in Paris, head to Normandy for the D-Day commemorations with heads of state and world leaders and then return to Paris where the Queen received the special honour of having a flower market named after her.
They rushed home so as not to miss attending the Investec Derby day at Epsom, Surrey - one of the Queen's favourite events in the horse racing calendar.
The Duke's busy schedule contrasts greatly with his previous two birthdays.
Last year, he spent his 92nd birthday in hospital after undergoing abdominal surgery. He stayed at the London Clinic for 11 days and spent two months convalescing.
In 2012, he left hospital just the day before his 91st birthday after falling ill with a bladder infection during the Diamond Jubilee celebrations and pulled out of several engagements in order to recuperate.
In May this year, the Duke had a 'minor procedure' carried out on his right hand at Buckingham Palace and was seen wearing a bandage to protect it. His engagements continued as planned.
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 Battenburg.
His early years were marked by upheaval after the Duke's family went into exile following a military coup in Greece which overthrew Philip's uncle, King Constantine I.
He moved first to Paris and then 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 and they married in 1947. Five years later, George VI died and Princess Elizabeth became Queen.
The Duke is the longest serving consort in British history and also the oldest serving partner of a reigning monarch.