The UB (Urzad Bezpieczenstwa/Security Office) was a shortened form of the official name Urzad Bezpieczenstwa Publicznego (Public Security Office), which was set up in early September 1944 in liberated territory of Poland by a team of NKVD agents parachuted into the country, later to be supervised by the NKVD rezident, General Selianovsky, thereby setting a standard of surrogacy that was to be copied across Eastern Europe as the NKVD inserted its own personnel or nominees into the newly created security structures.
In July 1946 the Ministry of Public Security was divided into eight departments, of which five dealt with operational matters: I, Counterintelligence; II, Technical Operations and Technology; III, Anti-opposition; IV, Protection of the Economy; and V, Counterinfiltration and Counter-Church Influence. Early in 1948 Department VII, handling general intelligence, was created and in June the following year the powerful and highly secret Biuro do spraw Funkcjonariuszy (Officer’s Office) was set up as an internal counterintelligence section in order to maintain surveillance and investigate and control ministry personnel.
On 2 March 1950 the Biuro Specjalne (Special Office), which became Department X in November 1951, was established to provide surveillance and to investigate senior Communists and their cronies. At the peak of its power two years later, the security service employed 33,200 officers, with the Ministry of Public Security controlling 57,500 Citizens Militia (MO); 41,000 crack troops of the intensely loyal Korpus Bezpieczenstwa Wewnetrznego (KBW, Internal Security Corps); 32,000 Wojska Ochrony Pogranicza (WOP, Frontier Guards); and an armed Industry Guard (SP, Straz Przemyslowa) to protect industrial plants against sabotage. In addition the regime could rely on 10,000 Straz Wiezienna (SW) prison guards and the 125,000-strong Ochotnicza Rezerwa Milicji Obywatelskiej (ORMO, Citizen’s Militia Voluntary Reserve), which consisted of low-level informers who in emergencies were armed with batons or guns and deployed against unarmed protesters. All these despised plainclothesmen were known as “ubeks” by the general population, which did not distinguish between the security service and the rest.
After Josef Stalin’s death, the power of the Ministry of Public Security diminished and in June 1954 the feared Department X was disbanded, with other changes limited to the removal of a dozen or so most compromised officers. On 7 December 1954 the Ministry of Public Security was divided into the Ministerstwo Spraw Wewnetrznych (MSW, Ministry of Internal Affairs) and subordinated to the Komitet do spraw Bezpieczenstwa Publicznego (KBP, Cabinet Committee for Public Security). Thus the MSW gained control over the MO, ORMO, WOP, KBW, SP, and SW, leaving the KBP as a de facto security service operating independently and outside the departmental structure of the previous Ministry of Public Security.
In September 1955 the KBP was reinforced by an amalgamation of the Informacja Wojskowa (Military Intelligence and Counterintelligence Service) and the Wojska Wewnetrzne, an internal military unit designed to prevent mutiny within the armed forces. Previously both had been subordinate to the Ministry of National Defense, but no announcement was made to explain the extension of the KBP’s power.
An order made in September 1955 committed the security service to support Informaca Wojskowa, and vice versa. Following the Twentieth Party Congress in Moscow, at which Nikita Khrushchev denounced Stalin, and the Poznan riots, the Polish Communist party disbanded the KBP as of November 1956. The Public Security Offices (UBPs) were dismantled and the hitherto informal security service was reduced in number and power, streamlined, and incorporated into Polish Ministry of Internal Affairs (MSW), where it was named officially the Security Service, the Sluzba Bezpieczenstwa (SB); the nickname “ubek” was so deeply rooted in the public mind, however, that it survived despite some competition from the new acronym “esbek.”