In July 1944, behind the Soviet front line, a brand new Polish provisional government was formed, called the Polish Committee of National Liberation (Polski Komitet Wyzwolenia Narodowego, PKWN).
It was established in Chełm on the initiative of Polish communists, in order to assume control over Polish territories re-taken from Nazi Germany by the advancing Red Army.
PKWN was proclaimed "the only legitimate Polish government" by Stalin, with full political control and Soviet sponsorship.
Within the PKWN's internal structure, there were thirteen departments called Resorty.
One of these was the Department of Public Security (Resort Bezpieczeństwa Publicznego) or RBP, headed by Stanisław Radkiewicz.
It was a precursor of the Polish communist secret police.

On December 31, 1944, the PKWN was joined by several members of the London-based Polish government in exile, among them Stanisław Mikołajczyk (later chased out of the country).
PKWN was then transformed into Provisional Government of Republic of Poland (Polish: Rząd Tymczasowy Rzeczypospolitej Polskiej or RTRP).
All departments were renamed: the Department of Public Security became the Ministry of Public Security (Ministerstwo Bezpieczeństwa Publicznego) or MBP and UB.
In July 1944, behind the Soviet front line, a brand new Polish provisional government was formed, called the Polish Committee of National Liberation (Polski Komitet Wyzwolenia Narodowego, PKWN). It was established in Chełm on the initiative of Polish communists, in order to assume control over Polish territories re-taken from Nazi Germany by the advancing Red Army. PKWN was proclaimed "the only legitimate Polish government" by Stalin, with full political control and Soviet sponsorship. Within the PKWN's internal structure, there were thirteen departments called Resorty. One of these was the Department of Public Security (Resort Bezpieczeństwa Publicznego) or RBP, headed by Stanisław Radkiewicz. It was a precursor of the Polish communist secret police.
On December 31, 1944, the PKWN was joined by several members of the London-based Polish government in exile, among them Stanisław Mikołajczyk (later chased out of the country). PKWN was then transformed into Provisional Government of Republic of Poland (Polish: Rząd Tymczasowy Rzeczypospolitej Polskiej or RTRP). All departments were renamed: the Department of Public Security became the Ministry of Public Security (Ministerstwo Bezpieczeństwa Publicznego) or MBP and UB.
Ministry of Public Security (Poland)