Nikola Tesla (July 9, 1856-January 7, 1943) was a Serbian-American electrical engineer, inventor and physicist who contributed to many of the developments in the field of electricity. "It’s generally agreed that Tesla was an earlier inventor of radio than Guglielmo Marconi, who won the patent and a Nobel Prize."
The SI unit measuring magnetic flux density or magnetic induction (commonly known as the magnetic field), is named the tesla, in his honor (see induction motor).
He was Thomas Edison's main rival at the end of the 19th century, even surpassing him in fame in the 1890s.
Despite the international fame he received as a result of his work involving alternating current, he died relatively penniless in a New York hotel room.