dashing!
History tells us that Tesla was something of an underdog; though famous in his own lifetime, he was considered an eccentric at best and a mad scientist at worst by his peers (not without reason). He was a friend of Mark Twain, a possible synaesthete, and a proponent of women's equality. He won the War of Currents against Edison (who was kind of a jerk, seriously - also, the accompanying video is NOT for the faint of heart, you have been warned), but Edison may be remembered better in part for his contributions to the light bulb. He worked on inventing the radio, but Marconi (also kind of a jerk, at least as far as radios are concerned) beat him out in the patent dispute and won the Nobel prize for it in 1909. In fact, here's a helpful comic from Hark! A Vagrant laying it all out: Tesla, Marconi, Edison.
However, he invented other stuff, too. Take this, for example:
The Tesla coil. What a celibate rock star!
Finally, Tesla may or may not have been responsible for the Tunguska Event in his quest to discover a super weapon. He even has a Cthulhu mythos connection: he might have been the inspiration for Lovecraft's Nyarlathotep (I don't see the resemblance myself).
