| 1084 BC | Greece | Greek poet Aeschylus records that in this year Queen Clytemnestra, at her palace in Argos, Greece, is informed of the fall of Troy and her husband Agamemnon's return by a system of signal fires – the first recorded telegraph system. |
| 1833 | Germany | German mathematician Carl Friedrich Gauss, and German physicist Wilhelm Eduard Weber, construct an electromagnetic telegraph. It uses two copper wires and a compasslike mechanism for detecting the electric current, and carries messages 2.3 km/1.4 mi over housetops in Göttingen. |
| 6 January 1838 | USA | The US artist and inventor Samuel Finley Breese Morse and financier Alfred Louis Vail make the first successful public demonstration of an electric telegraph. |
| 1844 | USA | The world's first telegraph line, connecting Washington, DC, and Baltimore, Maryland, becomes operational. |
| 1850 | UK | British inventor Francis Bakewell invents a ‘copying telegraph’ that can transmit images or print painted with varnish on one conducting roller to another. It is an early version of the facsimile machine and a forerunner of television. |
| 1853 | USA | The US inventor Richard Hoe improves his rotary press, developing the web press which can print 18,000 sheets per hour on both sides. |
| 6 December 1877 | USA | US inventor Thomas Alva Edison patents the phonograph. Recording involves the transmission of sound vibrations through a large horn and a diaphragm to a stylus, which inscribes a groove on a rotating wax cylinder. Reproduction of the sound is achieved by reversing the process. The first reproduction of a human voice occurs on the 29 November when Edison utters the words ‘Mary had a little lamb’. |
| 1894 | UK | At the annual meeting of the British Association for the Advancement of Science, British physicist Oliver Joseph Lodge gives the first demonstration of wireless telegraphy, transmitting signals over a distance of 60 m/180 ft; he fails to realize its practical implications. |
| June 1896 | UK | Italian physicist Guglielmo Marconi patents wireless telegraphy. In September, he gives public demonstrations, sending signals 6.4 km/4 mi over Salisbury Plain, England, and 14.5 km/9 mi over the Bristol channel. |
| 1900 | USA | Canadian-born US scientist Reginald Aubrey Fessenden discovers the principle of amplitude modulation (AM) of radio waves. |
| 12 December 1901 | | Italian physicist Guglielmo Marconi, in St John's, Newfoundland, Canada, receives the letter ‘S’ in Morse code, from Poldhu, Cornwall, England. It is the first transmission of a radio signal across the Atlantic Ocean, a distance of 3,200 km/2,000 mi, and it inaugurates the development of radio communication. |
| 4 July 1903 | USA, Philippines | Honolulu, USA, and Manila in the Philippines are linked by undersea cable. US president Theodore Roosevelt inaugurates transpacific communications by sending a message around the world via San Francisco, Honolulu, and Manila. It takes 12 minutes. |
| 1915 | | US physicist Manson Benedicks discovers that a germanium crystal can convert alternating current to direct current. This leads to the field of solid-state electronics, in the late 1940s. |
| 21 November 1931 | USA | The American Telephone and Telegraph Company (AT&T) introduces the first telex service. |
| 1939 | USA | The US inventor Edwin Armstrong constructs the first FM radio transmitter station. |
| 1947 | UK | The printed circuit board is developed by British scientist John Sargrove. Because the layout of wiring is planned, it greatly simplifies the production of radio and television. |
| 1950 | USA, Cuba | A coaxial telephone cable with submerged repeaters is laid between Miami, Florida, and Havana, Cuba; its success paves the way for transatlantic cables. |
| 10 July 1962 | USA, Europe | The US communications satellite Telstar is launched for the American Telephone and Telegraph company (AT&T) by the National Aeronautics Space Administration (NASA) from Cape Canaveral, Florida. Weighing 77 kg/170 lb and orbiting the Earth every 158 minutes, it is designed to receive a signal from the ground, amplify it, and then relay it to another ground station. Live television pictures of the chairman of the American Telephone and Telegraph company (AT&T) are transmitted from Andover, Maine, to Goonhilly Down, Cornwall, southwest England, and Brittany, France. Transmissions last only 15 minutes per orbit but they are the first to connect the television networks of Europe and North America. |
| June 1964 | UK, Netherlands | The Dutch electronics company Philips launches the compact cassette in Britain. This is still the industry standard for analogue audio cassettes. |
| 5 April 1965 | world | The first international communication satellite, Intelsat 1 (Early Bird), is launched into geostationary orbit over the Atlantic Ocean at the Equator. It provides 240 two-way telephone circuits or one television channel. |
| 1966 | UK | The British engineers Charles Kao and Georges Hockman of Standard Telecommunications Laboratories show that data can be carried on light transmitted over long distances in glass fibres rather than on electric currents in copper wire, leading to the development of fibre-optic cables. |
| 1970 | USA | The US military initiates the Global Positioning System (GPS), consisting of 21 satellites. An individual can determine his or her position anywhere on the Earth to within 23 m/75 ft by receiving the radio signals from a minimum of three satellites. |
| 1987 | world | As prices drop and the technology develops to improve the speed of transmission, fax machines become an established feature in offices. |
| 27 July 1988 | UK | The telecommunications company Mercury installs its first 26 payphones at Waterloo Station in London, England. |
| 5 February 1989 | UK | Satellite television is broadcast direct to homes in Britain via satellite dish decoders. Four Sky TV channels are available, featuring news, film, sport, and a general channel. |
| September 1990 | Japan | The Japanese company Sony launches the first DAT recorder for domestic use, the Sony DTC 55ES. |
