During the Mongol invasion of Hungary in 1241 the town was destroyed; it was re-populated under King Béla IV but even by the end of the 14th century it was still considered a village. King Zsigmond of Luxemburg, in an effort to develop the town, freed Szolnok from certain taxes in 1422, and from customs in 1429. After this, the town slowly began to grow and prosper again.