The Reformed Fortified Church in Târgu Mureş is situated northeast to the city centre, in the territory of the medieval fortress near the György Bernády Square. Its length is 57 m, the height of the main nave is 12 m. The church was built by Franciscan friars in the 14th century; their aim was to build a church of pilgrimage with a capacity of one thousand people next to their monastery. They finished the construction of one of the masterpieces of Late Gothic in 1490, year of king Matthias’s death. In the 16th century the inhabitants of Marosvásárhely supported Reformation and in the period 1557‒1559 the fortified church entered the possession of the Reformed community. Reformed religious education started in the monastery already in 1557. The birthday of the Reformed fortified church is celebrated on 1 November 1559; this was the date when the Synod of Marosvásárhely accepted John Calvin’s doctrine of the Holy Communion and the Helvetic trend of Reformation.
The church was not spared by war atrocities; in 1602 it was burnt by Basta’s troops; in 1658, when the Turks attacked George II Rákóczi, the ceiling of the nave fell down, the stained glass windows and the organ were destroyed. For years the church had no roof; it was partly restored from Mihály Teleki’s donation between 1685 and 1693. In the period 1785‒1791, under the guidance of the builder Anton Türk originating from Vienna, the church interior underwent great transformations. Its Baroque organ was built in 1789 by Johann Brause from Kronstadt; the gilding and painting were carried out by Márton Papp. The pulpit and its “crown” were made in 1841 by the joiner János Erdélyi, based on the plans of Count Ferenc Teleki, the library founder Sámuel Teleki’s son. The ornamental Lord’s table was commissioned by György Zalányi and was made in 1841 by the local joiner György Bertók. The church tower, with four spires, is 66 m high. A clock operated in the tower already at the beginning of the 1600s. The stairs leading to the tower were made by the Szekler handyman Péter Bodor. In 1892 a clock that indicated the time with toll was placed in the tower. The clock was made by clockmaker Benedek Müller from Southern Hungary. The tower clock did not work for seventy years; it was repaired by Pál Sántha, inhabitant from Csittszentiván/Sântioana de Mureş in 1972. The A 16.16 quintal bell of the tower was cast by János and Dániel Andrásofszki in Kolozsvár/Cluj in 1834. The small bell made in 1972 weighs 603 kg.
37 diets were held among the walls of the Fortified Church; king Louis the Great, John Hunyadi and John Sigismund were also among the church visitors. The latter, as the first Prince of Transylvania, consolidated the religious freedom declared on the Diet of Torda on 6-13 January 1568, on 6 January 1571. Francis II Rákóczi was elected Prince in the Fortified Church on 8 April 1707.