Tsardom of Bulgaria (1908–1946) in the context of "Ferdinand I of Bulgaria"

The People's Republic of Bulgaria (PRB; Bulgarian: Народна република България, НРБ, romanized: Narodna republika Bŭlgariya, NRB; pronounced [nɐˈrɔdnɐ rɛˈpublikɐ bɐɫˈɡarijɐ]) was the Bulgarian state existed from 1946 to 1990, ruled by the Bulgarian Communist Party (BCP; Bulgarian: Българска комунистическа партия (БКП)) together with its coalition partner, the Bulgarian Agrarian People's Union. Bulgaria was also part of Comecon as well as a member of the Warsaw Pact. The Bulgarian resistance movement during World War II deposed the Tsardom of Bulgaria administration in the Bulgarian coup d'état of 1944 which ended the country's alliance with the Axis powers and led to the People's Republic in 1946.

The BCP modeled its policies after those of the Soviet Union, transforming the country over the course of a decade from an agrarian peasant society into an industrialized socialist society. In the mid-1950s and after the death of Stalin, the party's hardliners lost influence and a period of social liberalization and stability followed under Todor Zhivkov. Varying degrees of conservative or liberal influence followed. After a new energy and transportation infrastructure was constructed, by 1960 manufacturing became the dominant sector of the economy and Bulgaria became a major exporter of household goods and later of computer technologies, earning it the nickname of "Silicon Valley of the Eastern Bloc". The country's relatively high productivity levels and high scores on social development rankings made it a model for other socialist countries' administrative policies.

The Radomir Rebellion, also known as Vladaya Uprising and Soldiers' Uprising, was a revolt by Bulgarian soldiers in 1918 during World War I in the Tsardom of Bulgaria.