In the 1st century B.C., with the expansion of the Roman Empire the Danube became the border line between the Roman and the Dacian worlds.

Dacia knew a remarkable flourishing under Decebal. After a first confrontation with the Roman Empire during the reign of emperor Domitian (A.D. 87-89), other two wars were necessary (101-102 and 105-106) for the Roman Empire, ruled then by emperor Trajan (97-117), to conquer Dacia. At the acme of its glory, the Roman Empire finally defeated Decebal and turned most of his kingdom into the Roman province of Dacia. Trajan's Column, raised in Rome, and the Triumphal Monument of Adamclisi (Dobrudja) evoke this military effort, continued by a massive and systematic colonization of the territories newly integrated in the empire. Despite the huge losses, the Dacians remained here, under the new rule, as the prevailing element, subject to a complex process of Romanization, with its essential attribute - the gradual but permanent adoption of the Latin language.

The autochthonous Daco-Roman population continued to live in Dacia even after the withdrawal of the Roman army and administration, on orders from Aurelian (270-275), south of the Danube. The ancestors of the Romanians remained for a few centuries, under the political, economic, religious and cultural umbrella of the Roman Empire, and then of the Eastern Roman Empire. Living in the old Roman settlements, the natives survived the successive waves of migratory peoples.

Concomitantly with the ethno-cultural Daco-Roman symbiosis, resulting in the 6th and 7th centuries in the making of the Romanian people, in the 1st-4th centuries the Daco-Romans adopted Christianity in its Latin "garb". Thus, at the end of its ethnogenesis, in the 6th and 7th centuries, the Romanian people emerged on the historical scene as a Christian people. This explains why, unlike other neighbouring peoples, featuring specific dates of Christianization (the Bulgarians - 865, the Serbians - 874, the Poles - 966, the Eastern Slavs - 988, the Magyars - year 1000), the Romanians have no Christianization date, being "Christian" by birth.

Between the 4th and 13th centuries, the Romanian people had to face the waves of migratory people - the Goths, the Huns, the Gepidae, the Avars, the Slavs, the Petchenegs, the Cumanians, the Tartars - crossing the Romanian territory.

The Slavs, settling as early as the 7th century south of the Danube, determined the displacement of the compact mass of Romanians in the Carpathian-Balkan space, isolating those north of the Danube (Daco-Romanians) from those in the south, the west and south-east of the Balkan Peninsula (the Macedo-Romanians, the Megleno-Romanians and the Istro-Romanians). The Slavs settling north of the Danube were eventually assimilated by the Romanian people.

The affiliation to Orthodoxism also determined the adoption by the Romanians of the old Slavonic language as a cult language and, beginning the 14th-16th centuries as a chancery and culture language. The Slavic language - never spoken by the Romanian people - had for the Romanians the same role as Latin played in the West during a certain period of the Middle Ages. In the early modern epoch it was replaced for good by the Romanian language, as far as cult, chancery and culture were concerned.

Beginning the 10th century, the Byzantine, Slavic and Magyar sources, and later the Western ones, mentioned the existence of some bodies politic of the Romanian population - kniezates and voivodates - initially in Transylvania and Dobrudja and then, in the 12th and 13th centuries, in the territories east and south of the Carpathians.

Despite the resistance of the Romanian bodies politic, in the 10th-13th centuries the Magyars managed to occupy Transylvania and include it in the Magyar Kingdom (up to late 16th century, as autonomous voivodate). In order to strengthen their position in Transylvania, where the Romanians remained, for centuries, the majority ethnic element, as well as to defend the southern and eastern borders of the voivodate, in the 12th and 13th centuries, the crown colonized the frontier areas with groups of Szecklers an Saxons.

Lying at a crossroads between three great empires and claimed by all of them, Wallachia, Moldavia and Transylvania were, for more than 150 years, both an object of dispute and a battlefield where the armies of the three empires confronted each other.

During the many wars fought by Russia and Austria against the Ottoman Empire (1710-1711, 1716-1718, 1735-1739, 1768-1774, 1787-1792, 1806-1812, 1828-1829, 1853-1856), the confrontations on the Romanian land, always doubled by a foreign military occupation, most often prolonged after the wars, generated waste, destruction, displacements of the population, and painful territorial amputations of the Romanian territories. Thus, Austria temporarily annexed Oltenia (1718-1739) and the northern part of Moldavia, Bukovina (1775-1918). After the Russian-Turkish war of 1806-1812, Russia annexed the eastern part of Moldavia, Bessarabia (1812-1918), the land locked between the Prut and the Dniester.

Notable economic and social changes took place in the 18th century and in early 19th century. Same as everywhere else in Europe, the national idea began to take shape, lying at the foundation of the future plans of the Romanian politicians. The union of a part of the Orthodox clergy in Transylvania with the Catholic Church (Greek-Catholics), achieved between 1699 and 1701, played an important part in the process of emancipation of the Romanians in Transylvania. Their struggle for rights equal with the three other nationalities (although they represented over 70 per cent of the Principalities' population, they were considered as tolerated in their own country) was initiated by bishop Inochentie Micu-Klein, and continued by the intellectuals grouped in the Transylvanian School movement.

The hopes for a change in Wallachia found their expression in the revolution led by Tudor Vladimirescu (1821). Despite the fact that the Ottoman and Tsarist troops put down the movement, the revolution led, nevertheless, to the abolition of the Phanariote regime and the appointing of native princes to the thrones of Moldavia and Wallachia.

In 1848, the revolutionary movements extended to the Romanian principalities as well, bringing remarkable names to the forefront of the political scene: Ion Heliade-Radulescu, Nicolae Balcescu, Mihail Kogalniceanu, Simion Barnu]iu, Avram Iancu a.o. In Moldavia the movements were soon stifled, but in Wallachia the revolutionaries actually stayed in power from June to September 1848. In Transylvania, the revolution lasted until 1849; the incapacity of the Magyar leaders to understand the justness of the Romanians' demands, and the forementioned leaders' decision to help Hungary annex Transylvania led to a split of the Romanian and Magyar revolutionary forces. The attempt of the Hungarian government to stop the Romanians' struggle came up against the fierce armed resistance led by Avram Iancu in the Apuseni Mountainns. Despite the brutal intervention by the Ottoman, Tsarist and Hapsburg armies, in 1848-1849, the renewing democratic ideas were assimilated all over the Romanian territories in the decade to follow.

After the War of Crimea (1853-1856), the status of the Romanian Principalities (Wallachia and Moldavia) acquired, at the Paris Peace Congress (February-March 1856), the dimensions of a European issue. Still under Ottoman suzeranity, Wallachia and Moldavia were placed under the guarantee of the seven powers signatories of the Paris Treaty. The seven protecting powers did, only to a small extent, endorse the Romanians claims. In Moldavia, on January 5-17, 1859, and in Wallachia, on January 24-February 5, 1859, the Romanians elected Alexandru Ioan Cuza as unique prince, achieving thus de facto, the union of the two principalities. On January 24-February 5, 1862, the Romanian nation state took the name of Romania, with Bucharest as the capital. Together with Mihail Kogalniceanu, his closest counsellor and co-worker, Alexandru Ioan Cuza initiated a programme of reforms to further update the structures of the Romanian society and state.

After the abdication of Alexandru Ioan Cuza in 1866, Carol of Hohenzollern-Sigmaringen was appointed ruling prince of Romania on May 10, 1866, as a result of a plebiscite. The New Constitution passed in 1866 (and remaining in force until 1923) proclaimed Romania a constitutional monarchy (1881).

Owing to favourable international circumstances, on May 9/21, 1877, Romania proclaimed her state independence. The Government headed then by Ion C. Bratianu, with Mihail Kogalniceanu as Foreign Minister, decided, on the Russians' request, that the Romanian troops joined the Russian ones operating on the anti-Ottoman front in Bulgaria. The Berlin International Peace Congress (June-July 1878) acknowledged Romania's independence, also re-establishing Romania's rights over Dobrudja, after a long Ottoman domination.

In Transylvania, the signing of the agreement stipulating the recreation of the Hungarian State, after more than three centuries of collapse, and the making of the Austrian-Hungarian dual state (1867) had serious consequences for the Romanians inhabiting this territory. Transylvania lost the autonomy she had enjoyed during the Austrian rule, being incorporated by Hungary. Budapest's legislation, proclaiming the existence of only one nation - the Magyar one - envisaged the destruction of the other nationalities through forced Magyarization. The Romanian National Party in Transylvania played an important role in the assertion of the Romanians' national identity, as it was the banner bearer of the fight for the acknowledgment of equal rights for the Romanian nationality and of the resistance against the denationalization projects. In 1892, the national struggle of the Romanians reached an acme through the Memorandum Movement, which called the attention of emperor Franz Joseph I and of the European public opinion to the Romanians' demands, and the intolerance of the Budapest government as to the national matter.

A period of stability and progress was registered in Romania between 1878 and 1914. The political life centred round two principal parties - the Conservative one (Lascar Catargiu, P.P. Carp, Gh. Grigore Cantacuzino, Titu Maiorescu etc.) and the Liberal one (Ion C.Bratianu, Dimitrie A. Sturdza, Ion I.C. Bratianu etc.); their alternative stay in power represented a characteristic feature of the political system at that time. Russia's expansionist policy determined Romania to sign, in 1883, a secret alliance treaty with Austria, Hungary, Germany and Italy, renewed, on a regular basis, until the beginning of WW1.

In August 1914, on the outbreak of WW1, Romania proclaimed her neutrality. Two years later she joined the Allies who had promised her support in achieving national unity. The government led by Ion I.Bratianu declared war to Austria-Hungary. After an initial success, the Romanian army was forced to withdraw to Moldavia. During the summer of 1917, in the great battles of Marasti, Marasesti and Oituz, the Romanians thwarted the Central Powers' attempts to get Romania out of the war by occupying the rest of the territory.

The objectives of the foreign policy during the inter-bella period - when Nicolae Titulescu played a remarkable role - envisaged the maintenance of the territorial status quo by creating regional alliances, supporting the League of Nations and the policy of collective security, as well as the promotion of a close collaboration with the Western democracies - France and Great Britain. In 1920-1921 together with Czechoslovakia and Yugoslavia, Romania laid the foundations of the Little Entente, and, in 1934, together with Yugoslavia, Greece and Turkey, Romania established a new organization of regional security - The Balkan Entente.

At the beginning of WW2, Romania proclaimed her neutrality (on September 6, 1939), but the defeats suffered by France and the U.K. in 1940 brought the country to a dramatic situation. Applying the provisions of the secret Soviet-German protocol of August 23, 1939, the Soviet government forced Romania to give up Bessarabia, the north of Bukovina and the Hertza land - which had never belonged to Russia - by the ultimatums of June 26th/28th, 1940. Italy and Germany helped Hungary take (on August 30, 1940) the north-western part of Transylvania with a Romanian majority population. After the Romanian-Bulgarian negotiations at Craiova, on September 7, 1940 a treaty was signed according to which the south of Dobrudja went to Bulgaria. The serious crisis in the summer of 1940 led to the abdication of King Carol II in favour of his son, Michael I (September 6th, 1940); soon after, General Ion Antonescu was to take the power (starting October 1941, he become a marshal).

Hoping to get back the territories lost in 1940, Ion Antonescu took part, alongside Germany, in the war against the Soviet Union (1941-1944). On August 23, 1944, Marshal Ion Antonescu was arrested by order of King Michael I. The new government, made of military and technicians, declared war on Germany (on August 24, 1944). Romania joined the United Nations, with all her economic and military forces, until the end of the war in Europe. Despite the great human and economic efforts for the cause of the United Nations, as demonstrated by the remaining nine months of war, the Peace Treaty of Paris (February 10, 1947) did not acknowledge Romania her status of cobelligerent country and compelled her to pay huge war compensations. Nevertheless, the treaty acknowledged north-eastern Transylvania as rightfully belonging to Romania; Bessarabia, northern Bukovina and the Hertza land remained annexed to the USSR.