The NKVD was the law enforcement agency of the Soviet Union that executed the will of the Communist Party. It contained regular police forces but was best known for operating the Gulag system of forced labor camps and conducting mass executions and deportations under Stalin. The NKVD stemmed from the Cheka secret police established after the Bolshevik Revolution and gradually expanded to become an all-union security force by 1934, responsible for detention facilities and the regular police in addition to state security.