Prince William: From birth to 40th birthday

Duke of Cambridge Prince William is celebrating his 40th birthday on June 21, today.

William Arthur Philip Louis was born on June 21, 1982, the first child of Prince Charles, the heir to the British throne, and Princess Diana, the most photographed woman of her generation.

At the age of 13, William became the first future monarch to attend Eton College, an exclusive private school west of London noted for having educated 19 British prime ministers.

In August 1997, a year after his parents were granted a decree absolute ending their 15-year marriage, William and his brother Harry joined their father at Balmoral Castle, the royal family's summer home in the Scottish highlands.

In September 2001 William arrived at St Andrews University in Scotland to begin a four-year degree course on the history of art.

The university saw a 44 percent increase in student applications - many from young women - after the handsome prince decided to enroll.

William acted as an official witness when his father married Camilla Parker Bowles in April 2005.

In June 2005 William graduated from St Andrew's University with an upper second class honours degree, becoming the most academically accomplished member of the royal family.

While at university the prince met Kate Middleton, the daughter of self-made middle-class entrepreneurs, and their relationship attracted intense interest in the royalty-obsessed tabloid media once they left the relative privacy of university life.

After a year at the elite Sandhurst military academy William graduated as an army officer in December 2006 and spent the next two years training with the army, airforce and navy in preparation for his future role as head of the armed forces.

In January 2009 he began an 18-month training course as a pilot with the Royal Air Force's Search and Rescue Force (SARF).

In January 2010 William carried out his first official overseas tour, visiting Australia and New Zealand as his grandmother's representative.

In the following November Buckingham Palace announced the engagement of William and his long-term girlfriend Kate Middleton.

The couple broke up briefly in 2007 but were finally married in April 2011 after a courtship that lasted nearly a decade.

More than a million people thronged London's streets and a worldwide audience of over 2 billion watched the sumptuous show of British pageantry which breathed new life into the monarchy.

To mark the marriage, the Queen made William the Duke of Cambridge and Kate became Her Royal Highness the Duchess of Cambridge.

For their first overseas tour the royal couple visited Canada and America in July 2011. They delighted cheering Canadians by showing their sporty side and taking part in dragon boat racing, with William giving Kate a consoling hug after his boat won.

In California they mingled with Hollywood A-listers at a BAFTA charity party held to raise money for the American Friends of The Foundation of Prince William and Prince Harry which is dedicated to preserving the environment, helping young people and those in the armed forces.

William and Kate then left on a nine-day tour of southeast Asia, as part of the Queen's Diamond Jubilee celebrations.

In December 2012 Buckingham Palace announced William and Kate were expecting their first baby. The palace was forced to reveal the information early after Kate was admitted to hospital with acute morning sickness.

Kate's growing baby bump was scrutinised the world over. One of the couple's last public engagements together prior to the birth was to a service held in Westminster Abbey marking the 60th anniversary of the Queen's coronation at the beginning of June.

The world's media began camping outside St Mary's hospital in central London well before Kate was finally admitted on July 22 and gave birth to the couple's baby boy - who is now third in line to the British throne, after his father and grandfather.

Prince George Alexander Louis was carried out by his proud parents the following day to meet the press and an enthusiastic crowd who cheered as Kate handed over the newest member of the royal family into the arms of Prince William.

Following his decision to step down from the military in September 2013 after more than seven years in the armed forces, William has devoted more time to royal duties and charity work.

The couple's younger child and only daughter Princess Charlotte of Cambridge was born in May 2015. Their third child Prince Louis was born in April 2018.

William was Prince Harry's best man for his dazzling wedding to Meghan Markle at Windsor Castle in May 2018. William's eldest two children, George and Charlotte, were among the bridesmaids and page boys for the wedding. Louis - who was just under four-weeks-old - did not attend.

In the past five years, William has received much praise for his work on mental health, homelessness and the environment, but the couple's recent tour of the Caribbean was a wake-up call after they faced protests over Britain's imperial past and criticism that some of the tour had echoes of a colonial throwback.

Prince William, his wife Kate and the rest of Britain's royal family recently celebrated the Platinum Jubilee, marking Queen Elizabeth's 70-year reign, with four days of festivities. (Reuters)