Defunct intelligence agencies

The '''People's Commissariat for Internal Affairs (, ), abbreviated as NKVD''' (; ), was the interior ministry and secret police of the Soviet Union from 1934 to 1946. The agency was formed to succeed the Joint State Political Directorate (OGPU) secret police organization, and thus had a monopoly on intelligence and state security functions. The NKVD is known for carrying out political repression and the Great Purge under Joseph Stalin, as well as counterintelligence and other operations on the Eastern Front of World War II. The head of the NKVD was Genrikh Yagoda from 1934 to 1936, Nikolai Ye

The All-Russian Extraordinary Commission, abbreviated as VChK (), and commonly known as the Cheka (), was the first Soviet secret police organization. It was established on by the Council of People's Commissars of the Russian SFSR, and was led by Felix Dzerzhinsky. By the end of the Russian Civil War in 1922, the Cheka had at least 200,000 personnel.

Soviet national security agency (1922-1923)

Soviet national security agency (1923-1934)

The Directorate of State Security (, DSSh), commonly called the Sigurimi (which in Albanian means "Security"), was the state security, intelligence and secret police service of the People's Socialist Republic of Albania. Its proclaimed goal was maintaining state security of Albania, which meant it de facto also served to suppress opposing political activity among the populace and preserve the existing political system. It was regarded as one of the most feared, most repressive, and most brutal secret police agencies to ever exist.

State Security (, ), or StB / ŠtB, was the secret police force in communist Czechoslovakia from 1945 to its dissolution in 1990. Serving as an intelligence and counter-intelligence agency, it dealt with any activity that was considered opposition to the Communist Party of Czechoslovakia and the state.

The International and State Defense Police (; PIDE) was a Portuguese security agency that existed during the Estado Novo regime of António de Oliveira Salazar. Formally, the main roles of the PIDE were the border, immigration and emigration control and internal and external state security. Over time, it came to be known for its secret police activities.

first created by the Hongwu Emperor (Ming Dynasty) in 1368 serving as his personal bodyguards; 1382 consolidated and broadened as a spy agency

thumb|upright|Inscription about a frumentarius from Legio VII Gemina.

paramilitary organization in the Ottoman Empire

Soviet national security agency (1934-1943)

former name for the Bulgarian secret service

The Santebal (Khmer: សន្តិបាល, "Keeper of Peace") was the secret police and security apparatus of Angkar (The Organization) in Democratic Kampuchea (DK). It was an integral part of Marxist-Leninist and Maoist structure of the Communist Party of Kampuchea (CPK), which serves the party—referred to "Angkar" by purging "traitorous" elements which targets anyone including all foreigners (westerners) had suspected of opposing the party, including intellectuals, ethnic minorities (Vietnamese). The Khmer Rouge captured Phnom Penh on 17 April 1975, declared "Year Zero," and began the forced evacuation

late Roman Imperial Courier Service

military unit

Turkish intelligence organization in the Ottoman Empire

Ming dynasty secret police agency

former Mexican intelligence agency

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The barīd (, often translated as "the postal service") was the state-run courier service of the Umayyad and later Abbasid Caliphates. A major institution in the early Islamic states, the barid was not only responsible for the overland delivery of official correspondence throughout the empire, but it additionally functioned as a domestic intelligence agency, which informed the caliphs on events in the provinces and the activities of government officials. A new barīd was established during the Mamluk period.

security agency in Egypt

Salvadoran paramilitary organization

Republic of China military intelligence bureau (1932-1946), also known as the Clandestine Investigation Section of the National Revolutionary Army

Police agency tasked with suppressing Communism under Batista in Cuba

Portuguese criminal police body active between 1969 and 1974

The Hangash (), an acronym standing for Defence Security Agency, was a notorious secret police unit of the Siad Barre regime in Somalia until his overthrow in 1991.

The areani or arcani were a force of the Roman Empire, based in Roman Britain during the later part of the Roman occupation of the island. They had played some part in the campaign of Constans in Britain in 343; later they helped to instigate the Great Conspiracy in 367-368. Due to their participation in the Conspiracy, Count Theodosius disbanded them.