Reghin was first mentioned in 1228 as a town called Regun in Hungary, though evidence suggests it may have been founded earlier under King Ladislaus I. Despite damage from Mongol and Cuman invasions in the 13th century, Reghin developed rapidly and became the residence of influential families. It established as an ecclesiastical center in 1330 with the construction of a Gothic church that still stands today as the largest in the area, housing the oldest medieval Latin inscription in Transylvania.