In 1919, at the age of twenty, Beria started his career in state security when the security service of the Azerbaijan Democratic Republic hired him while he was still a student at the Polytechnicum. In 1920 or 1921 (accounts vary) Beria joined the Cheka, the original Bolshevik secret police. At that time, a Bolshevik revolt took place in the Menshevik-controlled Democratic Republic of Georgia, and the Red Army subsequently invaded. The Cheka became heavily involved in the conflict, which resulted in the defeat of the Mensheviks and the formation of the Georgian SSR. By 1922, Beria was deputy head of the Georgian branch of Cheka's successor, the OGPU.