Guglielmo Marconi (1874-1937), Italian physicist, holding his most famous invention, the radio. Privately tutored in his youth, Marconi had developed his first radio device by the age of 21. It had a range of around 1.5 kilometres, attracting the interest of the British government. Marconi patented his system in Britain and, in 1897, established the Marconi's Wireless Telegraph Company in London. In 1899 he made the first transmission across the English Channel and, in 1901, the first trans-Atlantic transmission. In 1909 he was awarded the Nobel Prize in Physics. He later developed short-wave radio and established a global radio telegraph network.