Johnny Weissmuller was one of the world’s first star athletes. Weissmuller swam his way into the record books, setting more than 50 world records and winning five Olympic gold medals. He parlayed his success in the pool into Hollywood stardom, where nearly a century later he is still well known for his role as Tarzan.

And yet, Weissmuller’s most important maneuver was not known until after he passed away in 1984 at age 79.

Weissmuller, it turned out, was born in Austria-Hungary and came to the United States as an infant. His family first moved to western Pennsylvania and then to Chicago. At age nine, having contracted polio, it was suggested that Weissmuller try swimming.

“My doctor said I should take up some sort of exercise to build myself up,” Weissmuller said. “I got into a swimming pool at the YMCA and liked it. And I found I had a natural flair for it.”

Weissmuller thrived in the water, eventually qualifying for the Paris 1924 Olympic Games. It was then that his nationality could have become an issue, as Weissmuller applied for an American passport and assumed his younger brother’s identity.

In The Olympics, Weissmuller won gold in the 100- and 400-meter freestyle, as well as the 4×200-meter freestyle relay, and helped the United States win a bronze in water polo. Four years later, at the Amsterdam 1928 Olympic Games, Weissmuller took gold in the 100-meter freestyle and 4×200-meter freestyle relay.

Weissmuller retired from amateur competition unbeaten and worked as a swimsuit model. He then screen tested for the role of Tarzan and starred in 12 films – becoming just as famous for his Tarzan yell as for his fast times in the pool.