Michael Phelps was born on June 30, 1985.
As a 15-year-old in 2000, Phelps became the youngest male swimmer to earn a spot on the U.S. Olympic team in 68 years. He took fifth place in the 200 butterfly.
As the 2004 Olympics in Athens approached, expectations for Phelps were high as he qualified for six individual events and two relays. Phelps broke a world record on in his very first event, the 400-meter medley. The Baltimore native took home six gold medals and two bronze.
When 2008 came around, the question was whether he'd be able to break Mark Spitz's record of seven gold medals. Not only did he win eight golds, but Phelps also set world records in every event but one.
He added four more gold medals in 2012.
He holds the record for most gold medals ever (18), which is twice more then any other Olympian.
Phelps recently announced that he will attempt to compete in the 2016 Olympics, which take place in Rio de Janeiro.