Ian Thorpe has shocked the world of swimming by retiring at the age of 24.
Ian Thorpe celebrates 200m gold in the 2004 Olympics in Athens
Born in Sydney on 13 October, 1982, the Australian won numerous Olympic, World and Commonwealth titles. He also set numerous world records, several of which still stand.
Here are 10 facts you may or may not know about one of the pool's greatest performers:
1. He is allergic to chlorine.
2. He took an interest in swimming when sister Christina was advised it would help strengthen a broken wrist.
3. At 6ft 5in tall with size 17 feet, he has several nicknames, chief among them "Thorpedo", "Thorpie" and "Human Fish".
4. He has his own line of jewellery and has also worked as an underwear model.
5. Thorpe is the only swimmer to win six gold medals in one World Championships - he achieved the feat in 2001 - and has a total of 11 world titles.
6. He is Australia's most decorated Olympian with nine medals - five gold, three silver and a bronze.
7. At 14, he became the youngest male to ever represent Australia and a year later became the youngest individual world champion following his victory in the 400m freestyle at the 1998 World Championships.
8. Thorpe was in New York on 11 September 2001 and was on his way to the World Trade Center when the first hijacked plane struck the Twin Towers.
9. He has broken 22 world records and still holds world marks in the 200m and 400m freestyle as well as being a member of the world record-holding 4x200m freestyle relay team.
10. He beat Pieter van den Hoogenband and Michael Phelps in the 200m final at the Athens Olympics in 2004. The contest was described as the "race of the century".