Mikhail Gorbachev is chosen as General Secretary of the Soviet Communist Party and goes on to launch the policies of perestroika and glasnost.
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.
A team at the Pasteur Institute including Françoise Barré-Sinoussi and Luc Montagnier reports the virus later named HIV, the cause of AIDS.
Argentina seizes the Falkland Islands; Britain dispatches a task force and retakes the islands after a 74-day conflict.
Tim Berners-Lee submits "Information Management: A Proposal" at CERN, the origin of the World Wide Web.
East Germany opens its border and crowds cross the Berlin Wall, a symbol of the Cold War's end.
Peaceful protests in Czechoslovakia bring an end to Communist rule; Václav Havel is elected president.