The Duke of Edinburgh has been the Queen's steadfast companion for nearly 70 years.

Known for his no-nonsense approach and acerbic wit, Prince Philip is the longest-serving consort in British history and also the oldest serving partner of a reigning monarch.

The husband of one of the most famous women in the world, he is defined by his relationship to Elizabeth II and gave up a promising naval career to support his wife in her royal role.

While the Queen takes centre stage, Philip has always been one step behind, ready to lend a hand.

The Duke has had a profound effect on the development of the British monarchy and has been a moderniser of 'the Firm'.

In private, he is head of the family. To the public, he is the irascible figure who speaks his mind despite the consequences.

He fought for Britain during the Second World War, serving with distinction in the Royal Navy.

As a younger man he was a good shot, a first-class polo player, accomplished sailor, enthusiastic cricketer and international four-in-hand carriage driver.

Hardworking and inquisitive, he has dedicated himself to national life for decades and even when he gave up some of his charitable associations when he was 90, he has still been associated with more than 800 charities.

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 his family went into exile following a military coup in Greece which overthrew his uncle, King Constantine I.

George V, the Queen's grandfather, ordered the Royal Navy cruiser HMS Calypso to evacuate the family and Philip was carried to safety in a cot made from an orange box on December 1922, aged just 18 months.

His parents split up and he rarely saw either of them - with his mother, who suffered from mental illlness, being confined to an asylum.

After spending a year at a school in Germany, he eventually went to Gordonstoun School in Morayshire.

Philip later joined the Royal Navy and, while a cadet, he caught the eye of a 13-year-old Princess Elizabeth - a distant cousin - when she visited the Britannia Royal Naval College in Dartmouth with her parents, the King and Queen.

During the Second World War, he saw active service from the Indian Ocean to the Mediterranean, and by 1945 was in Tokyo Bay as the Japanese surrendered.

In 1947, two years after the end of the war, the Princess married dashing, blond Philip in Westminster Abbey.

He renounced his Greek title and became a naturalised British subject, and was made Duke of Edinburgh by the King.

The Duke and the Princess had the first of their four children, Charles, now the Prince of Wales, in 1948 and Anne, now the Princess Royal, in 1950.

Their lives changed forever when George VI died at Sandringham on February 6 1952 and Princess Elizabeth became Queen.

Philip - whose naval career had come to an end - had to a define a new role for himself as his wife diligently took to her duties as head of state.

He accompanied the Queen around the world on Commonwealth tours and state visits and across the UK.

He became involved with hundreds of organisations and set about modernising Buckingham Palace, Sandringham and Balmoral.

In 1956, he set up the Duke of Edinburgh's Award - inspired by his time at Gordonstoun and his mentor and headmaster Dr Kurt Hahn.

It has become one of the country's best-known youth self-improvement schemes, with million across the globe gaining their bronze, silver and gold awards.

After a gap of 10 years, the Queen and Philip welcomed two more children - Andrew, now the Duke of York, in 1960, and Edward, now the Earl of Wessex, in 1964.

The Duke has been depicted as a tough but caring father. Hewitnessed first-hand the troubles faced by the Windsors in the 1990s - from the scandal surrounding Sarah, Duchess of York - who was caught having her toes sucked by her financial adviser - to the fall out of Charles and Diana's War of the Waleses.

When the Princess of Wales died suddenly in a car crash in 1997, Philip joined Charles, Princes William and Harry, and Diana's brother, Earl Spencer, in the solemn procession behind her funeral cortege.

The Duke also helped the Queen through the deaths of both her mother and sister in the Golden Jubilee year of 2002.

He has enjoyed good health throughout much of his life - recovering from a blocked coronary artery in 2011 and a bladder infection in 2012 - the latter leading him to miss the majority of the Queen's Diamond Jubilee celebrations.

He continued to take part in fast-paced, dangerous carriage-driving events, competing at international level until the age of 85.

When he turned 90 in June 2011 he insisted on no fuss, but the Queen bestowed on him a new title - Lord High Admiral, titular head of the Royal Navy.