Italian inventor and radio pioneer Guglielmo Marconi in front of a telegraph in the laboratory aboard his yacht "Electra", circa 1935.

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Inventors around the world were churning out new and exciting inventions left and right in the years leading up to the 20th century. Scientific work in radio technology was heating up too. Two men in particular, Serbian-American scientist Nikola Tesla and Italian physicist Guglielmo Marconi went head-to-head in what would become the race to invent the radio. But more than 100 years later, ask any two people who invented the radio and you're likely to get two different answers. The story is a murky one that mixes scientific discovery with lawsuits and good old-fashioned marketing. Let's see if we can untangle the threads.

After emigrating to the U.S. in 1884, Tesla invented the induction coil or Tesla coil, a device essential to sending and receiving radio waves and one the U.S. Patent Office would later say Marconi relied on for his work [source: Britannica]. But in 1895, a fire destroyed Tesla's lab as he prepared to send a radio signal approximately 50 miles (80 kilometers) to West Point, N.Y. [source: PBS].

Meanwhile, Marconi had been conducting his own experiments and in 1896, sent and received Morse code-based radio signals at distances spanning nearly 4 miles (6 kilometers) in England. That same year, he applied for, and was granted, the world's first patent in wireless telegraphy in England [source: Nobel Prize].

Tesla applied for his first patents in radio work in 1897 in America. He also built and demonstrated a radio-controlled boat at Madison Square Garden in 1898. Here's where things get sticky.

In 1900, the U.S. Patent Office granted Tesla patents 645,576 and 649,621, the fundamental design of the Tesla coils, on March 20 and May 15 respectively. Tesla's radio patents gave him ownership over one of the key necessities in radio communications. That same year, on Nov. 10, Marconi filed patent No. 7777, for tuned telegraphy.

At first the patent office denied Marconi's applications on the grounds that his work relied on the use of Tesla coils [source: PBS]. Unfazed, Marconi used his father's connections and wealth to spearhead a profitable business based on his telegraph technology while continuing to pursue his radio patents. In 1901, he transmitted the first transatlantic telegraph.

Marconi reapplied for three years while he gained financial support from company investors Andrew Carnegie and Thomas Edison. Finally in 1904, the U.S. Patent Office inexplicably reversed its earlier decision and gave the Italian the patent for invention of the radio.

Marconi won the Nobel Prize for physics in 1909 [source: Nobel Prize], further fueling the rivalry with Tesla. In 1915, Tesla sued the Marconi Company for patent infringement to no avail. Marconi had won. Or had he?

In an ironic twist of fate, Marconi's company sued the U.S. government in 1943 for patent infringement during World War I. But the case never made it to court. Instead, to avoid the lawsuit altogether, the U.S. Supreme Court upheld patent 645,576, thus restoring Tesla (who had died a few months earlier) as the inventor of the radio. Nevertheless, many people still tend to think of Marconi as the father of the radio.