In the first century BC Dacian and other Thracian tribes form in present-day Romania a independent state of Dacia. Dacia is conquered by the Roman Empire in 106 and it becomes the province of Dacia. The Dacians mingle with the Roman conquerors. After the collapse of the Roman power in this region under Gothic pressure in 271 the area is under control of diverse peoples like the Goths, the Gepides, the Huns, the Assyria, the Kumans and the Pechenegians. Since the sixth century slavonic tribes enter the area, followed in the ninth century by Hungarians. Large parts become part of Hungary.

In 1324 the Principality of Hungaro-Walachia or in Romanian Muntenia becomes a fact, followed in 1352 by a second principality, the Principality of Moldavia. Both principalities have to accept in 1411 Ottoman sovereignity. Although formally Ottoman sovereignity remains continued, the principalities become de facto Russian protectorates in 1828.

As a result of the Crimean war the principalities become independent and form in 1859 a personal union. They merge in 1861 into Romania, formally the United Romanian Principalities, renamed Romania in 1866. Romania becomes fully independent in 1878 and in 1881 it becomes the Kingdom of Romania. During this time Romania has a two party system, but the alternation of power is provoked by the monarch. Every time when he appoints a new prime minister, the new premier appoints new civil servants who can influence the results of the upcoming elections. This changes in 1914, after the Balkan Wars, the power of the king is minimalized. Under prime minister Ionel Brătianu (1914-1918) of the liberal Partidul Naţional Liberal (National Liberal Party, PNL) universal male suffrage is introduced.

After the defeat of Austria-Hungary in World War I, the region of Transsylvania is added to Romania, as is the Russian region of Bessarabia. Romania becomes a parliamentary democracy. Most of Romania's pre-World War II governments maintain this form. Between 1918 and 1922 Artur Vaitoianu, Alexandru Vaida-Voevod of the conservative Partidul Naţional Romān (Romanian National Party, PNR), Alexandru Avarescu of the personalist Partidul Poporului (People's Party, PP) and Dumitru Take Ionescu of the conservative Partidul Conservator-Democrat (Conservative Democratic Party, PCD) are prime ministers. Brătianu returns in office in 1922. The PNL is defeated at the 1926 elections by the PP of Alexandru Avarescu, but in 1927 Brătianu becomes prime minister again. He is succeeded in 1927 by Vintila Brătianu.

The PNL rule ends in 1928. The Partidul Naţional-Ţărănesc (National Peasant's Party, PNŢ) rules until 1933 with the prime ministers Iuliu Maniu (1928-1930, 1930), Gheorghe G. Mironescu (1930, 1930-1931, 1932-1933), Nicolae Iorga (1931-1932) and Alexandru Vaida-Voevod (1932 and 1933). The PNL regains power in 1933 with prime ministers Ion Gheorghe Duca (1933). He is shortly after his inauguration assassinated. Constantin Angelescu (1933-1934) and Gheorghe Tătărescu (1934-1937) take over. In 1937 Octavian Goga of the PNC becomes prime minister. The fascist Garda de Fier (Iron Guard) movement, exploiting nationalism, fear of communism and resentment of alleged foreign and Jewish domination of the economy, is a key destabilizing factor, which leads to the creation of a royal dictatorship in 1938 under King Carol II. He forms the Frontul Renaşterii Naţionale (Front of National Rebirth, FRN), later renamed Partidul Naţiunii (Party of the Nation, PN).

In 1940 the authoritarian General Antonescu took control. Under his rule Romania enters World War II on the side of the Axis Powers in 1941, invading the Soviet Union to recover Bessarabia and Bukovina, which had been annexed in 1940. In 1944 the USSR occupies the country. It presses for inclusion of Romania's heretofore negligible Communist Party in the post-war government, while non-communist political leaders are steadily eliminated from political life. King Mihai I abdicates under pressure in 1947, when the Romanian People's Republic is declared. Romania has to cede Bessarabia to the USSR, that forms the Moldavian Socialist Soviet Republic.

Romania is ruled by the Partidul Muncitoresc Romān (Romanian Workers' Party, PMR, later named Partidul Communist Romān (Romanian Communist Party, PCR), lead by Gheorghe Gheorghiu-Dej. He is succeeded after his death by Nicolae Ceausescu in 1965. That year the counry is renamed Socialist Republic of Romania. After a popular uprising presidential democracy is introduced in 1989. Ceausescu is executed. The country is renamed Romania and an impromptu governing coalition, the Frontul Salvarii Naţionale (National Salvation Front, FSN), installs itself and proclaims the restoration of democracy and freedom. Ion Iliescu, a former Communist Party official demoted by Ceausescu in the 1970s, emerges as the leader of the FSN. He wins the presidential elections of 1990 against candidates of the pre-war PNŢ and PNL and the FSN captures a majority in parliament. After the support of the president of attachs by miners agains the opposition, the government of prime minister Petre Roman falls and a technocrat, Theodor Stolojan, leads an interim government.

In 1992 Ion Ilescu is re-elected and his new party, the Frontul Democratiei Salvarii Naţionale (Democratic National Salvation Front, FSDN) wins a plurality. With the support of nationalist and communist parties, Nicolae Vacaroiu forms a government. In 1993 the FDSN is renamed Partidul Democratiei Sociale din Romania (Party of Social Democracy of Romania, PDSR). At the 1996 elections Emil Constantinescu of the PNŢ wins in the Democratic Convention (CDR) the elections and becomes president. The CDR joins the PD, the PNL and the Hungarian minority party in a coalition. Victor Ciorbea is named prime minister. Ciorbea is succeeded in 1998 by Radu Vasile (PNŢ) and in 2000 by the non-partisan Constantin Mugur Isarescu. The 2000 general elections bring back both the PDSR with Adrian Nastase as prime minister and Ion Iliescu as president. The PDSR is reorganized in 2001 into the Partidul Social Democrat (Social Democrat Party, PSD).