15 photos of a young Prince William that will make you swoon
- Prince William, who is second in line to the throne, turns 39 on June 21.
- Before he became the charitable royal we know today, he was a heartthrob in the early 2000s.
- Photos show the young prince during polo matches and his military career.
- Visit Insider's homepage for more stories.
At a Red Cross drive for tsunami victims in 2005, Prince William helped pack up supplies.
His blue sweater was embroidered with a Red Cross pin.
Prince William rocked a casual look to an IRB Rugby Aid Match at Twickenham Stadium in March 2005.
Prince Harry, then age 21, wore a baseball cap while chowing down on a hamburger in the background.
That same month, while playing in a charity polo match, Prince William looked dapper in a blue striped rugby shirt and a white turtleneck.
Dubbed the "sport of kings," polo is a family tradition — both Prince William and Prince Harry have played it since they were very young.
While on a family ski trip in Switzerland in 2005, Prince William posed alongside his father, Prince Charles.
Prince William also brought his then-girlfriend Kate Middleton on the family ski trip after rumors of their relationship first emerged two years earlier.
They were spotted by paparazzi cruising the slopes, although the royal family often organizes official photo-calls like this one to avoid getting snapped by other photographers on their vacations.
Prince William looked especially dashing at his father's wedding ceremony to Camilla Parker Bowles on April 9, 2005.
He was photographed alongside his cousin, Zara Phillips, the daughter of Princess Anne and Mark Phillips and the eldest granddaughter of Queen Elizabeth II.
Prince William and Camilla's son, Tom Parker Bowles, both served as witnesses at the ceremony.
Prince William was spotted looking sporty at Cirencester Park Polo Club on June 5, 2005.
Prince William is a surprisingly good polo player, especially given the fact that he's left-handed and polo is required to be played using the right hand.
In fact, Prince William's 7-year-old son, Prince George, appears to be following in his father's polo-playing footsteps.
While attending a royal polo match, the young prince was photographed playing around with a polo mallet — and just like his father, he was holding it with his left hand!
The 23-year-old prince supported Team Thailand at the Chakravarty Cup Polo match between Team Thailand and Team Dubai on June 11, 2005.
His popped collar epitomized early 2000s fashion.
The young prince appeared to beam with pride after graduating from St. Andrews University in Scotland in June 2005.
Prince William had turned 23 a few days prior.
Before officially beginning his military career in January 2006, Prince William attended a Christmas Day service in a smart navy sport coat and a blue tie.
The young royal, who is second in line to the throne, looked dashing in his Christmas best.
Prince William has had an illustrious military career.
In 2006, he was made Commodore-in-Chief of the Royal Navy Submarine Service.
Prince William also spent time training with the Royal Navy at Britannia Royal Naval College in June 2008.
Prior to this two-month-long attachment, Prince William completed a similar attachment training with the Royal Air Force.
Despite training with other sects of the British armed forces, Prince William spent the majority of his military career as a pilot with the Royal Air Force Search and Rescue Force.
Though he began his training in 2008, he was officially stationed at a search-and-rescue base on the Welsh island of Anglesey in 2010.
According to CNN, he lived at the base along with Catherine, the Duchess of Cambridge.
Prince William still took time, however, to attend charity events and give back to his community.
Prince William is pictured here in 2007, playing a game of football with a group of young people during the FA's Hat-Trick Project at Westgate Community College.
In his younger days, the Duke of Cambridge would also take brief time off from his role in the military to spend the holidays with his family.
Prince William, age 26, is pictured here attending the Christmas Day service at St Mary Magdalene Church on December 25, 2008.
While we usually see Prince William clean-shaven, he looked undeniably more grown-up with facial hair. It's rumored the prince grew the beard to disguise his identity during a Special Boat Service mission prior to beginning his RAF pilot training, according to The Telegraph.