Transylvania is a mountainous area in the Eastern part of the Carpathian Basin, which itself is part of the Danubian Basin. The first known agricultural settlers came to Transylvania around 5000 BC from the Near East: at first, from Central and Eastern Anatolia, up through the Balkans and the Danubian Basin.

The Central and Eastern Anatolian peoples were part of a larger ethno-linguistic group which also included the peoples of the Caucasian, Northern Mesopotamian, and Caspian ("Western Iranian") regions. These ancient Near Eastern peoples formed a distinct ethno-linguistic group which was neither Semitic, nor Indo-European, and which inhabited these regions before the appearance of the Semitic and Indo-European peoples. The Sumerians of Southern Mesopotamia, who originated from Northern Mesopotamia, also belonged to this distinct ethno-linguistic group, along with the Anatolian Hatti, the Northern Mesopotamian Hurrians and Subareans, and the Kassites, Elamites and Medes of Western Iran. Historical, archeological, anthropological, and ethno-linguistic research has demonstrated that the Turanian peoples of Eurasia (the Scythians, Parthians, Huns, Avars, Khazars, Magyars, and the Ural-Altaic peoples) also originate from this Anatolian-Caucasian-Caspian-Mesopotamian ethno-linguistic group.

Around 5000 BC, this ethno-linguistic group began to expand, and settled in the Mediterranean and Danubian Basins. These pre-Indo-European settlers of ancient Europe became known as the pre-Hellenic Aegean peoples, the Etruscans, and the Iberians (ancestors of the Basques). The Illyrians and Thracians of the Balkans also originated, at least in part, from these pre-Indo-European peoples.

Around 3000 BC, another wave of settlers came to Transylvania, and this time there were Mesopotamian Sumerians among them. This is evidenced by the archeological findings in Transylvania which include artifacts with Sumerian pictographs (writing symbols).

During the 1st Millennium BC, the Carpathian Basin was part of the realm of the Scythians. Around 300 BC, Thracians from the Eastern Balkans were also thought to have migrated North to Transylvania. The Thracians were believed to have been part of the so-called "Getae" people of Eastern Europe, who themselves were most likely Scythians, thus the Thracians were probably related to the Scythians. The Dacians, who emerged in Transylvania during the 2nd century BC, were most likely the descendents of the Scythians and Thracians who had populated this region.

In 107 AD, after decades of warfare and fierce resistance, Dacia was conquered by the Roman Empire. The Roman invasion and occupation of Dacia was genocidal as the Dacian population was decimated, and the survivors were enslaved and deported. However, in 271 AD, the Romans evacuated the province of Dacia due to the pressure of the Goths, who were themselves pushed Westward by the Huns of Central Eurasia.

By the 5th century AD, the Huns were in control of the entire Carpathian Basin, including Transylvania. Around 550 AD, the Avars began to establish themselves in the Carpathian Basin, and by 560 they were in Transylvania also. After the Hun Empire of the 5th century, the Avar Empire was unquestionably one of the most powerful empires of Europe from the late 6th century to the end of the 8th century AD. In 896 AD, the Magyars established their state in the Carpathian Basin, and Transylvania became a part of Hungary for over 1000 years.

The historical record thus shows that during the nearly 6000 years from the appearance of the first settlers from the Near East to the arrival of the Magyars, the population of Transylvania, along with the rest of the Carpathian Basin, was predominantly non-Indo-European, and would remain so until the end of the Middle Ages, as successive waves of ethno-linguistically related Near Eastern and Turanian peoples settled there.

Starting around 1000 AD, the forced Western Christianization of Hungary brought an increase in foreign influences and foreign settlers. As a result, during the 12th and 13th centuries, Saxons were settled in Southern Transylvania. They were granted wide-ranging privileges at the expense of the indigenous Hungarian population as the Saxons imposed exclusive and discriminatory policies. In the 13th c. a group of Teutonic Knights also sought to establish itself in Transylvania, but their attempt to carve out a separate state from the territory of the Hungarian Kingdom led to their expulsion from Hungary. In the latter part of the 12th century, Vlachs appeared for the first time in Transylvania. They were nomadic shepherds who had migrated North from the Balkans during the previous centuries. They were a Balkanic people speaking a latinized language resulting from the centuries of Roman rule and influence in the Balkans. As they moved North towards the Danubian Basin, they were also influenced by the cultures of the Turanian peoples they came in contact with and through whose territories they passed: the Bulgars, the Petchenegs, the Cumans, and the Magyars.

Since the establishment of the Hungarian state in 896 AD, Hungary was the major power in the Middle and Lower Danubian Basin - until the end of the Middle Ages (15th c.). The Kingdom of Hungary extended beyond the Carpathian Basin, and controlled areas to the South (Northern Balkans), and East: Havasalföld and Moldavia, to the South and East of Transylvania. However, the Medieval Hungarian Kingdom suffered a major defeat in the 16th c. against the advancing Ottoman Empire. As a result, Hungary was divided into three parts: Western and Northern Hungary came under Habsburg rule, Central and Southern Hungary came under Ottoman occupation, and in the East, Transylvania became a semi-independent principality under the protectorate of the Ottoman Empire. During 150 years, Hungary was devastated by the war between the Habsburgs and the Ottomans. During this time, Hungarian-ruled Transylvania took part in the struggle for Hungarian national interests - freedom and unity - against foreign rule and occupation.

At the end of the 17th c. the Ottomans were expelled from Hungary, but the Habsburgs took advantage of a weakened and devastated Hungary to take over the entire country, including Transylvania. Although the Transylvanian Hungarian princes resisted in the early 18th c. against the Habsburg usurpation of the Hungarian Crown, they were unable to prevent it. Thus, Hungary came under the control of the Habsburg Empire. Until the 16th c., the Hungarians constituted the majority of the Carpathian Basin's population, and this was also the case in Transylvania, but as a result of the following centuries of warfare which caused great losses to the Hungarian population, and the massive foreign colonization carried out by the Habsburgs, the Hungarians became a minority in their own land. In 1848-49, another major Hungarian national uprising erupted against the Habsburgs. As a result of the Habsburg policy of divide and rule, various ethnic groups settled in Hungary turned against the Hungarians. In Transylvania, Vlach armed bands slaughtered entire Hungarian villages. The Hungarians were nevertheless able to defeat their enemies, until the Russians intervened upon Habsburg request, and crushed the Hungarian uprising due to their numerical superiority. A period of severe Habsburg repression followed, but in 1867, a so-called "compromise" took place between the Habsburgs and Hungary, whereby Hungary obtained domestic autonomy, but the military, finances, and foreign policy remained under Habsburg control. This would effectively doom Hungary as it was dragged by Austria into the First World War.

In 1919, after the end of WWI, Rumania invaded Transylavania and the adjoining parts of Eastern Hungary. In 1920, the so-called "Treaty" of Trianon gave these Hungarian territories to Rumania. Approximately 50% of the population in the Hungarian territories annexed by Rumania were Vlachs who had migrated there since the Middle Ages, and who now referred to themselves as "Rumanians". As soon as the Rumanians took over Transylvania, they proceeded to eradicate the more than 1000 years of Hungarian presence. As a result of this policy of anti-Hungarian discrimination and ethnic cleansing, Hungarians were forcibly expelled, assimilated, their property confiscated, and their rights violated. During WWII, Hungary managed to liberate Northern and Eastern Transylvania, but the Rumanians re-occupied these territories following the Soviet invasion of Hungary in 1944. During this invasion, the Rumanians also committed atrocities against the Hungarian population, perpetrating massacres in Hungarian-inhabited areas. To this day, the Rumanian perpetrators of these anti-Hungarian atrocities have not been brought to justice and the Rumanian policy of anti-Hungarian discrimination and ethnic cleansing is still in force, as the Rumanian authorities resort to a variety of tactics aimed at forcing Hungarians to leave or to assimilate, and also at reducing their proportion of the Transylvanian population by settling more Rumanians from other parts of the country.

For further reference:
THE RUMANIAN POLICY OF ETHNIC ERADICATION DIRECTED AGAINST THE TRANSYLVANIAN AND MOLDAVIAN HUNGARIANS