A team at the Pasteur Institute including Françoise Barré-Sinoussi and Luc Montagnier reports the virus later named HIV, the cause of AIDS.
ARPANET officially switches to the TCP/IP protocol suite, often regarded as the birth of the modern Internet.
Argentina seizes the Falkland Islands; Britain dispatches a task force and retakes the islands after a 74-day conflict.
Mikhail Gorbachev is chosen as General Secretary of the Soviet Communist Party and goes on to launch the policies of perestroika and glasnost.
The World Health Assembly officially declares smallpox eradicated, the first human infectious disease to be wiped out.
After strikes at the Gdańsk shipyard, Poland's government accepts the right to form independent trade unions, opening the way for Lech Wałęsa's Solidarity movement.
Reactor No. 4 of the Chernobyl nuclear power plant in Soviet Ukraine explodes, spreading radioactive material across Europe in the worst nuclear accident in history.