The first country that existed on the present territory of Romania was Dacia. Yes, exactly like the Romanian brand of cars – now you know it. The inhabitants of Dacia were the Dacians – Indo-European people, closely related to the Thracians. The union between the Dacian tribes, all in one country, was made by the Dacian King Burebista (82-44 BC). This rich and prosperous country, having lots of natural resources such as gold, salt and forests, was partially conquered in 106 AD by the Roman Empire. For a period of 165 years we were under Roman administration and a strong Latin colonization took place on these territories by bringing Latin speaking people who settled and mixed with the original Dacian population. In 271, The Roman administration was withdrawn from Dacia and the mixture between the Dacians and the Roman colonizers formed the basis of the future nation.
In ethnic terms, Romanians are mostly Balkan people by the Dacian roots. First of all because the entirety of Dacia was not conquered by the Romans, and second, because after the Romans left, the territory was repopulated by the Dacians. At the same time we are also Latin due to the Latin colonization and the mixture of population.
In terms of language, due to Roman administration and Latin colonization, the Latin language was imported by the Romans and it continues to form the main part of the Romanian language so far. Today, the Romanian language is Latin with Slavic, Hungarian, German and Turkish influences from the medieval period when the Romanian territory was divided into 3 principalities: Transylvania, Wallachia and Moldavia. These influences are the result of the Slavic invasions between the 7th and 9th centuries, the Hungarian occupation and German colonization starting with the 12th century, continuing in the 19th century with Habsburg occupation in Transylvania and the Ottoman domination between the 14th and 19th centuries in Wallachia and Moldavia. But still, the Romanian language is one of the five Latin languages spoken in Europe, together with Italian, Spanish, French and Portuguese.
In terms of religion, the first people living on Romanian territory were baptized as Christians by St. Andrew, who later became the patron saint of Romania. Just like in other places, the Christians were persecuted by Romans until 313, when Constantine the Great legalized the Christian religion. After the Great Schism in 1054, when the Christian church was divided into 2 main churches: Catholic with its seat in Rome and Orthodox with its seat in Constantinople, the Romanian principalities started having more influence from Constantinople, due to its geographic proximity. In the first half of the 14th century the Orthodox Metropolitan Church of Wallachia was founded. Later on, in the first half of 15th century the Orthodox Metropolitan Church of Moldavia was founded. Transylvania belonged to the Catholic Church until the mid-19th century, when the Orthodox Metropolitan Church of Transylvania was founded. In 1872 the Metropolitan Orthodox Churches of Moldavia & Wallachia reunited forming the Romanian Metropolitan Orthodox Church, recognized by Constantinople later in 1885. In 1919 the Orthodox Metropolitan Church of Transylvania joined the Romanian Orthodox Metropolitan Church. Later, in 1925, the Romanian Orthodox Metropolitan Church rose to the rank of Patriarchate Church and became completely independent of The Orthodox Church of Constantinople.
This is how Romania became the only Orthodox Latin country in the world.