Royal of the day: The other William
Prince William of Gloucester was like the royal family's Buddy Holly - he was cool, young, handsome, and met his premature end in a tragic plane accident.
Prince William was a hero to his younger first cousin once removed, Prince Charles, who went on to name his first-born son after him (the Wills of today we all know and love).
His life story has been overshadowed by his present-day namesake, and he is sometimes referred to as the "forgotten" Prince William.
He was born on December 18, 1941, to Prince Henry and Princess Alice, Duke and Duchess of Gloucester. He was the grandson of King George V.
At five years old, the wee prince got his first taste of the royal limelight, as a page boy in his cousin Princess Elizabeth's wedding to Philip, Duke of Edinburgh in 1947.
He received his education at Wellesley House Preparatory School, Broadstairs, Kent and - like present-day William - Eton College.
He attended Magdalene College at the University of Cambridge, and graduated with a degree in history. He also spent a year at Stanford University studying political science, American history and business.
When his head wasn't in his books, the dreamboat prince was a bit of a man-about-the-town. He enjoyed nightclubs, and drove a high-powered sports car. He was also a keen polo player, skier, and a trained pilot.
After university, Prince William veered from the royal tradition of joining the army, instead choosing a career in the diplomatic service - becoming only the second member of the royal family to do so.
He got a job at the British High Commission in Nigeria, and later served as a junior diplomat at the British Embassy in Tokyo.
It was in Japan that he fell in love with a beautiful Hungarian-born ex-model, Zsuzsi Starkloff. Unfortunately, she was Jewish, seven years his senior and a divorcee.
This was unacceptable to the royal family, and when William wrote home telling of his intentions to propose, he was sternly discouraged.
William ultimately put loyalty to his family before love, and after four years, cooled the relationship off.
He would remain a bachelor for the rest of his short life. On August 28, 1972, he was competing in an air race near Wolverhampton when he crashed after take-off.
The 30-year-old prince and his co-pilot were killed instantly.
Prince William was buried at Frogmore, the royal burial ground at Windsor Castle. His legacy now lives on only in name, with the man who will one day be King.