In Transylvania and Banat, the beginnings of a feudal architecture date back to the X-XI centuries, materialized in the citadels of Biharia and Satu Mare, as well as those from Cenad, Cluj and Făgăraş. At the end of the 11th century a first cathedral was built in Alba Iulia, in the form of a three-nave Romanic basilica.

The oldest churches preserved from that time are the stone basilica of Cisnadioara, as well as the basilicas of Cisnadie, Ocna Sibiului, Chirpar, etc., all of them Romanesque.

The oldest Orthodox churches are monuments from the sec. XII-XIII, such as the Church of Streisângiorgiu, the Church of Densus, those in Gurasada, Sântămărie-Orlea, Strei, which show the confluence between the Balkan architecture and the Roman-Gothic architecture.

Romanic in Transylvania
The Romanic in Transylvania, represented in particular by ecclesiastical architecture (sacral), and some representations of the plastic art, penetrated through Benedictine sites from the 12th-13th centuries. Most of the edifices were destroyed during the great Mongol invasion, after which they either fell into ruins or were rebuilt in the Gothic style.

History
The first Roman monument is certainly St. Michael’s Cathedral in Alba Iulia (end of the 11th century).

In the Sibiu area there are also a series of three-nautical basilicas with Renaissance inspiration (Cisnădioara, Cisnădie, Găsteriţa, New Săsesc etc.).

In northern Transylvania, the main Romanic monuments are inspired by Benedictine site at Pannonhalma, also in the three-nave basilica (Acas, Herina, etc.).

Romanic edifices in Transylvania
Sacred edifices
Reformed church in Acas (former Benedictine monastery)
Reformed church in Budesti
The fortified church of Cincu
St. Michael’s Church in Cisnadioara
Evangelical Church in Herina
Reformed church in Luncani
The Assumption Church of Strei
Reformed church in Uileacu Şimleului (former Benedictine monastery)
St. Michael’s Cathedral in Alba Iulia

Secular buildings (civilian or military)
Donojanele from Cheresig (Bihor County) and the Graves Fortress in Gârbova (Alba County).
Fortresses Feldioara (Braşov County), Colţesti (Alba County), Câlnic (Alba County) and Deva (Hunedoara County).
All these secular Romanic buildings date back to the 13th century.

Gothic in Transylvania
The Gothic in Transylvania has developed since the 13th century, being represented in particular by the Saxon ecclesiastical and military architecture. This style was introduced by the Cistercian monks who came from France to build monastic settlements in the Kingdom of Hungary.

History
The Gothic style was introduced in Transylvania by the Cistercian monks by building the church of the Cârţa monastery (1202-1205). About the same time, the Hungarian authorities were brought to the province by the Teutonic knights, but also the Saxon settlers, who took over this style and perfected it, giving rise to true masterpieces of secular and religious architecture.

The Saxons built numerous fortifications and settlements in the Transylvanian cities, such as Sibiu, Brasov, Medias, Sighisoara, Cluj, Dej and Bistrita. A special phenomenon in Transylvania is the presence of many Saxon Gothic churches, with approximately 180-200 edifices. Their vast majority are fortified churches, being fenced by walls and bastions, which is an adaptation to the many invasions of the time. In the Gothic churches of Transylvania, two types are predominantly architectural plan: churches with three ships and hall churches, specific to German geographic space and North Europe. A main feature of the Transylvanian Gothic is the synthesis of the Romanic and Gothic elements, which is seen in many edifices. Over time, there was a close link between the German colonists in Transylvania and the Gothic sites in the German and the Kingdom of Bohemia, especially the cities of Nuremberg and Prague, this confirming the quality of the Transylvanian Gothic.

Gothic edifices in Transylvania

Sacred edifices
The Black Church in Brasov
St. Michael’s Church in Cluj
The Evangelical Cathedral in Sibiu
The Evangelical Church in Bistrita
Evangelical Church in Sebeş
Church of the Hill in Sighisoara
The fortified church in Biertan
Reformed church in Cluj
The fortified church of Harman
The fortified church of Prejmer
St. Bartholomew Church in Brasov
The fortified church in Feldioara
St. Margareta Church in Medias

Secular buildings (civilian or military)
Bran castle
Hunedoara Castle
Sighisoara Citadel
The fortress of Târgu Mureş

Baroque in Transylvania
Baroque Transylvanian style developed in the 18th-19th centuries, following the integration of the Transylvanian Principality into the Austrian Empire, which knew the age of the Austrian Baroque era.

The main Baroque cities in Transylvania are Cluj, Oradea, Târgu Mureşul, Sibiu etc., plus the Baroque centers in Banat, first of all Timişoara. The first edifice built in Baroque style is the Church of the Piarists of Cluj (1718-1724).

Examples

Ecclesiastical Architecture
The Basilica of Oradea
The Jesuits Church in Cluj
The Trinity Cathedral in Blaj
Cathedral of Nativity of St. John of Arad
Church of St. John the Baptist in Târgu Mureş
The Moon Church in Oradea
The Church of St. Ladislau in Oradea
The Church of Saints Peter and Paul in Brasov
St. George Cathedral in Timisoara

Secular Architecture
Bánffy Palace in Cluj
Brukenthal Palace in Sibiu
The Baroque Palace in Oradea
Baroque houses in Turda
Casa Karácsonyi in Gherla

Military Architecture
Alba Iulia Fortress
Arad Fortress

Source from Wikipedia