The Franciscan minority order received in 1486 on Ulița Lupilor (currently Mihail Kogălniceanu street) a place from the municipality. With the financial support of King Matthias Corvinus, at whose intervention they received the land, the Franciscans built an imposing church in the style of the late Gothic. The architect who supervised the work was a monk, a specialist in the construction of such buildings. The church dedicated to St. Mary was completed in 1516, during the Reformation it was abandoned and then taken over by the Jesuits. After the 1600s it is destroyed, being rebuilt according to the original project by Prince George Rákóczi II. Gothic style specialists are brought from the Baltic States to restore the ogival arches. Once rebuilt, the church becomes the cathedral of the Calvinist Reformed Church in Transylvania.
The church is a classic Gothic room-type construction with star-shaped arches systems. The most important art object is the pulpit from the 17th century, the work of a Polish sculptor. One of the two pipe organs is one of the largest in Transylvania. It is functional, during the summer it is used weekly for classical music concerts. Inside the church are exhibited the most important collection of funerary coats of arms of the Hungarian aristocracy of Transylvania. The church is the princely necropolis of the last two princes of Transylvania, Michael Apafi I and Michael Apafi II, who are buried with their wives inside this cathedral.