Harry Houdini was born Erik Weisz, but that name wasn't going to cut it for his magical ambitions. The origin of "Harry" was simple—he'd gone by "Ehrie" as a kid, so he just Americanized the old nickname. "Houdini" was an homage to one of the pioneers of modern magic, Jean Eugene Robert-Houdin. Robert-Houdin was a clockmaker who opened his own magic theatre in 1845. He's widely credited with being the first to perform in evening attire instead of fantastical robes, thus making magic a little more mainstream. Oddly enough, Houdini turned on his magical namesake later in life, writing a book called The Unmasking of Robert-Houdin in which he criticized Robert-Houdin for stealing other magicians' tricks.