Radio had many fathers, but Guglielmo Marconi made it real: the Italian sent wireless signals across his parents' estate in 1895, patented wireless telegraphy in Britain in 1896, and on 12 December 1901 received the first transatlantic signal — three dots for the letter S — in Newfoundland from Cornwall. He shared the 1909 Nobel Prize in Physics for it.
The waves themselves were predicted by James Clerk Maxwell's equations and proven by Heinrich Hertz in 1887, who generated and detected them in his Karlsruhe laboratory. Marconi's genius was not discovering the waves but taming them: better antennas, grounding, and the tuner that let one station be heard among many — the system that became global wireless communication.