First Republic of Armenia
On December 4, 1920, the Red Army entered Yerevan, the government of Armenian Republic effectively stopped working. On December 5, the Armenian Revolutionary Committee (Revkom; made up of mostly Armenians from Azerbaijan) also entered the city. Finally, on the following day, December 6, Felix Dzerzhinsky's dreaded secret police, the Cheka, entered Yerevan, thus effectively ending the existence of the Democratic Republic of Armenia.