Maramureș in the context of "Day of the Unification of the Romanian Principalities"

Transylvania (Romanian: Transilvania [transilˈvani.a] or Ardeal; Hungarian: Erdély [ˈɛrdeːj]; German: Siebenbürgen [ˌziːbm̩ˈbʏrɡn̩] or Transsilvanien; Transylvanian Saxon: Siweberjen) is a historical and cultural region in Central Europe, encompassing central Romania. To the east and south its natural border are the Carpathian Mountains and to the west the Apuseni Mountains. Broader definitions of Transylvania also include the western and northwestern Romanian regions of Crișana and Maramureș, and occasionally Banat. Historical Transylvania also includes small parts of neighbouring Western Moldavia and even a small part of south-western neighbouring Bukovina to its north east (represented by Suceava County).

Transylvania is known for the scenery of its Carpathian landscape and its rich history, coupled with its multi-cultural character. It also contains Romania's second-largest city, Cluj-Napoca, and other very well preserved medieval iconic cities and towns such as Brașov, Sibiu, Târgu Mureș, Bistrița, Alba Iulia, Mediaș, and Sighișoara. It is also the home of some of Romania's UNESCO World Heritage Sites such as the Villages with fortified churches, the Historic Centre of Sighișoara, the Dacian Fortresses of the Orăștie Mountains and the Roșia Montană Mining Cultural Landscape.

Greater Romania (Romanian: România Mare) is the Kingdom of Romania during the interwar period, within its borders achieved after the Great Union; or the related pan-nationalist ideal of a nation state which would incorporate all Romanian-speakers.

In 1920, after the incorporation of Transylvania, Bukovina, Bessarabia and parts of Banat, Crișana, and Maramureș, the Romanian state reached its largest peacetime geographical extent (295,049 km). Today, the concept serves as a guiding principle for the unification of Moldova and Romania.

Roman Dacia (/ˈdeɪʃə/ DAY-shə; also known as Dacia Traiana (Latin for 'Trajan’s Dacia'); or Dacia Felix, lit. 'Fertile Dacia') was a province of the Roman Empire from 106 to 271–275 AD. Its territory consisted of what are now the regions of Oltenia, Transylvania and Banat (today all in Romania, except the last region which is split among Romania, Hungary, and Serbia). During Roman rule, it was organized as an imperial province on the borders of the empire. It is estimated that the population of Roman Dacia ranged from 650,000 to 1,200,000. It was conquered by Trajan (98–117) after two campaigns that devastated the Dacian Kingdom of Decebalus. However, the Romans did not occupy its entirety; Crișana, Maramureș, and most of Moldavia remained under the Free Dacians.

After its integration into the empire, Roman Dacia saw frequent administrative reorganization. In 119 under Hadrian, it was divided into two departments: Dacia Superior ("Upper Dacia") and Dacia Inferior ("Lower Dacia"; later named Dacia Malvensis). Between 124 and around 158, Dacia Superior was divided into two provinces, Dacia Apulensis and Dacia Porolissensis. The three provinces would later be unified in 166 and be known as Tres Daciae ("Three Dacias") due to the ongoing Marcomannic Wars. New mines were opened and ore extraction intensified, while agriculture, stock breeding, and commerce flourished in the province. Roman Dacia was of great importance to the military stationed throughout the Balkans and became an urban province, with about ten cities known and all of them originating from old military camps. Eight of these held the highest rank of colonia. Ulpia Traiana Sarmizegetusa was the financial, religious, and legislative center and where the imperial procurator (finance officer) had his seat, while Apulum was Roman Dacia's military center.

The Hungarian minority of Romania (Hungarian: romániai magyarok, pronounced [ˈromaːnijɒji ˈmɒɟɒrok]; Romanian: maghiarii din România) is the largest ethnic minority in Romania. As per the 2021 Romanian census, 1,002,151 people (6% of respondents) declared themselves Hungarian, while 1,038,806 people (6.3% of respondents) stated that Hungarian was their mother tongue.

Most ethnic Hungarians of Romania live in areas that were parts of Hungary before the Treaty of Trianon of 1920. Encompassed in a region known as Transylvania, the most prominent of these areas is known generally as Székely Land (Romanian: Ținutul Secuiesc; Hungarian: Székelyföld), where Hungarians comprise the majority of the population. Transylvania, in the larger sense, also includes the historic regions of Banat, Crișana and Maramureș. There are forty-one counties of Romania; Hungarians form a large majority of the population in the counties of Harghita (85.21%) and Covasna (73.74%), and a large percentage in Mureș (38.09%), Satu Mare (34.65%), Bihor (25.27%), Sălaj (23.35%), and Cluj (15.93%) counties.

The union of Transylvania with Romania was declared on 1 December [O.S. 18 November] 1918 by the assembly of the delegates of ethnic Romanians held in Alba Iulia. The Great Union Day (also called Unification Day), celebrated on 1 December, is a national holiday in Romania that celebrates this event. The holiday was established after the Romanian Revolution, and celebrates the unification not only of Transylvania, but also of Bessarabia and Bukovina and parts of Banat, Crișana and Maramureș with the Romanian Kingdom. Bessarabia and Bukovina had joined with the Kingdom of Romania earlier in 1918.

The Second Vienna Award was the second of two territorial disputes that were arbitrated by Nazi Germany and Fascist Italy. On 30 August 1940, they assigned the territory of Northern Transylvania, including all of Maramureș and part of Crișana, from the Kingdom of Romania to the Kingdom of Hungary.

The Middle Ages in Romania began shortly after the withdrawal of the Roman legions from the former Roman province of Dacia in the late 3rd century and with the start of the Early Middle Ages and the Migration Period that followed afterwards respectively. It subsequently came to an end with the reign of Domn Michael the Brave (1593–1601) who managed, for a short time between 1599 and 1600, to rule Wallachia, Moldavia, and Transylvania together, the three principalities whose territories were to be united some three centuries later to form modern and contemporary Romania.

Over most of this period, Banat, Crișana, Maramureș, and Transylvania – now regions in Romania to the west of the Carpathian Mountains – were part of the Kingdom of Hungary. They were divided into several types of administrative units, such as "counties" and "seats". The heads of the Transylvanian counties or "counts" were subordinated to a special royal official called voivode, but the province was seldom treated as a single unit, since the Székely and Saxon seats were administered separately. In the kingdom, Romanian peasants, being Orthodox, were exempt from the tithe, an ecclesiastical tax payable by all Roman Catholic commoners. However, Romanian noblemen slowly lost the ability to participate in political life, as the 14th-century monarchs pursued a zealous pro-Catholic policy. Their position became even worse after 1437 when the so-called "Union of Three Nations", an alliance of the Hungarian noblemen, the Székelys, and the Saxons, was formed in order to crush the Bobâlna peasant uprising.

About 9.3% of Romania's population is represented by minorities (the rest of 77.7% being Romanians), and 13% unknown or undisclosed according to 2021 census. The principal minorities in Romania are Romani people, and Hungarians (Szeklers, Csangos, and Magyars; especially in Harghita, Covasna, and Mureș counties), with a declining German population (in Timiș, Sibiu, Brașov, or Suceava) and smaller numbers of Poles in Bukovina (Austria-Hungary attracted Polish miners, who settled there from the Kraków region in contemporary Poland during the 19th century), Serbs, Croats, Slovaks and Banat Bulgarians (in Banat), Ukrainians (in Maramureș and Bukovina), Greeks (Brăila, Constanța), Jews (Wallachia, Bucharest), Turks and Tatars (in Constanța), Armenians, Russians (Lipovans, in Tulcea), Afro-Romanians, and others.

To this day, minority populations are greatest in Transylvania and the Banat, historical regions situated in the north and west of the country which were former territorial possessions of either the Kingdom of Hungary, the Habsburgs, or the Austrian Empire (since 1867 the dual monarchy of Austria-Hungary until World War I).