On September 11, 1973, tanks rumbled through the streets of Chile, terrified civilians were lined up before firing squads at the National Stadium and many cities around the country. The Chilean Armed Forces staged a military coup to overthrow the constitutionally elected Popular Unity (UP) government of Salvador Allende, which proposed a peaceful transition to socialism. President Allende died in the La Moneda presidential palace, and his ministers and collaborators were arrested and sent to concentration camps. Many of them were later killed or made to disappear. Through Decree Law No. 5, announced September 12, 1973, the Armed Forces declared the existence of an "internal war" in the country.
Thus began 17 years of dictatorship, which ended March 11, 1990. Within a few hours, the social conflict which had permeated Chilean society immediately before the coup was defined as a "war" and the concept of the "enemy within" as well as the National Security Doctrine were imposed throughout the nation. The enemy within was the Communist, the Marxist, the poor, the Socialist, the revolutionary, the subversive, indeed, anyone perceived by the military to constitute a challenge to the new established order.
A state of siege was declared throughout Chile and was extended, except for brief periods, until 1987. This meant that all legal cases involving infractions of State of Siege regulations were transferred from the civilian courts to war-time military institutions.
These military concepts were used to justify the repression and killing unleashed upon Chile’s population. The repression was not limited to one part of Chile, nor did social class, gender, profession, civil status or age limit it.
Thousands of people were detained throughout Chile on the day of the coup and the days that followed. Summary executions, disappearances and killings in false-armed confrontations became the norm. Neighbours, colleagues and others began denouncing each other, a practice encouraged by the military Junta and which became part of Chilean society at the beginning of the dictatorship.
In 1988, after a period of negotiations with some sectors of the opposition to the dictatorship, the regime called a plebiscite as planned in the 1980 Constitution. In the plebiscite, the head of the regime and of the Army, General Augusto Pinochet, proposed the continuation of his government and of his leadership. Pinochet lost the plebiscite, which meant he was obliged to call presidential elections. Patricio Aylwin, a Christian Democrat, won these elections and on March 11, 1990, was sworn in as president, thus initiating a new period of transition to democracy in Chile.