1946 Bulgarian republic referendum in the context of "Bulgarian Communist Party"

Simeon Borisov Saxe-Coburg-Gotha (Bulgarian: Симеон Борисов Сакскобургготски, romanized: Simeon Borisov Sakskoburggotski, [simeˈɔn boˈrisof sakskoburˈɡɔtski]; born 16 June 1937) is a Bulgarian politician who reigned as the last Tsar of the Tsardom of Bulgaria as Simeon II from 1943 until 1946. In 1946, the monarchy was abolished by a referendum, forcing Simeon into exile. Following the fall of communism in Bulgaria, Simeon returned to his home country in 1996, and founded the National Movement for Stability and Progress party (also known as the National Movement Simeon II party). After winning the 2001 election as its leader, Simeon proceeded to govern Bulgaria as prime minister of the Republic of Bulgaria from 2001 to 2005.

Simeon was six years old when his father Boris III of Bulgaria died in 1943. Royal power was exercised on his behalf by a regency council led by Simeon's uncle Kiril, Prince of Preslav, General Nikola Mihov and prime minister, Bogdan Filov.

Saxe-Coburg and Gotha (German: Sachsen-Coburg und Gotha), or Saxe-Coburg-Gotha (German: Sachsen-Coburg-Gotha [ˈzaksn̩ ˈkoːbʊʁk ˈɡoːta]), was an Ernestine duchy in Thuringia ruled by a branch of the House of Wettin, consisting of territories in the present-day states of Thuringia and Bavaria in Germany. It lasted from 1826 to 1918. In November 1918, Charles Edward, Duke of Saxe-Coburg and Gotha, was forced to abdicate. In 1920, the northern part of the duchy (since 1918 the Free State of Gotha; culturally and linguistically Thuringian) was merged with six other Thuringian free states to form the Free State of Thuringia: Saxe-Weimar-Eisenach (until 1918 a grand duchy), Saxe-Altenburg and Saxe-Meiningen (until 1918 duchies), Schwarzburg-Rudolstadt and Schwarzburg-Sondershausen (until 1918 principalities), as well as the People's State of Reuss (until 1918 the principalities of Reuss-Gera and Reuss-Greiz). The southern part of the duchy (since 1918 the Free State of Coburg; culturally and linguistically Franconian), as southernmost of the Thuringian states, was the only one which, after a referendum, became part of the Free State of Bavaria.

The name Saxe-Coburg-Gotha also refers to the family of the ruling House of Saxe-Coburg and Gotha, which played many varied roles in the dynastic and political history of Europe in the 19th and 20th centuries. In the early part of the 20th century, before the First World War, it was the family of the sovereigns of the United Kingdom, Belgium, Portugal, Bulgaria, and Saxe-Coburg-Gotha. In 1910, the Portuguese king was deposed, and the same thing occurred in Saxe-Coburg-Gotha in 1918 and in Bulgaria in 1946 (although effective control had already ceased two years prior due to a coup). As of 2025, a branch of the family still reigns in Belgium, and while the British line still technically exists up to the present day, it now uses the name Windsor due to a proclamation issued by King George V in 1917. The former Tsar of Bulgaria, Simeon II (reigned 1943–46), kept his surname while serving as the Prime Minister of Bulgaria from 2001 to 2005.

The Fatherland Front (Bulgarian: Отечествен фронт, ОФ, romanized: Otechestven front, OF) was a Bulgarian pro-communist political resistance movement, which began in 1942 during World War II. The Zveno movement, the communist Bulgarian Workers Party, a wing of the Bulgarian Agrarian National Union and the Bulgarian Social Democratic Workers Party all became part of the OF. The constituent groups of the OF had widely contrasting ideologies and had united only in the face of the pro-German militarist dictatorship in Bulgaria. At the beginning, the members of the OF worked together, without a single dominating group. Professional associations and unions could be members of the front and maintain their organisational independence. However, the Bulgarian Communist Party soon began to dominate. In 1944, after the Soviet Union had declared war on Bulgaria, the OF carried out a coup d'état (9 September 1944) and declared war on Germany and the other Axis powers. The OF government, headed by Kimon Georgiev of Zveno, signed a ceasefire treaty with the Soviet Union (28 October 1944). In the summer of 1945 most of BANU led by Nikola Petkov and most of the Social-Democrats had left the OF and became a large opposition group which later on after the 1946 Grand National Assembly election would become a coalition named "Federation of the village and urban labour" with 99 MPs out of 465.

On November 18, 1945, the OF won a large majority in national elections. In November 1946 Georgiev resigned as Prime Minister and was succeeded by Georgi Dimitrov, leader of the communists. Bulgaria became a People's Republic on 15 September 1946 after a referendum. In 1948 and 1949 all the remaining parties in the OF save for the pro-communist wing of the BANU self-dissolved and merged into the BCP. The OF eventually transformed into a wide-ranging popular front under overall Communist control.