They surrendered to James I and, on September 16, 1251, the Conquering King gave it to the Catalan nobleman Guillem de Montcada. Three years later, Guillem de Montcada being in the castle of Onda, authorized 37 settlers to found Sa Pobla de Moncofa in the area of the castle of Nules; for that time he had to authorize other settlers to found Sa Pobla de Nules.

He granted Guillem Ramón de Montcada the privilege of bringing water from the Millars to the end of the castle of Nules. The right to the waters of the Millars made possible the transformation of large areas of the area into orchards and, as a consequence, the establishment of an important group of settlers.

He confirmed the sale that Ramón de Montcada had made to his son-in-law, Gilabert de Centelles, of the castle and town of Nules.

He died in the Sardinian campaigns. During the minority of his son Gilabertó (1320-1326), large areas of the area of Nules were transformed into orchards, with the consequent demographic growth.

The lord of Nules obtained from this monarch the confirmation of the right of waters and the holding of a market, as well as the privilege of having a jetty on the beach of Nules and the holding of an annual fifteen-day fair.

The great danger faced by the entire region of La Plana, which was invaded by the Castilians, Pere el Cerimoniós, in 1375, authorized the fortification of the town of Nules.

During the time of Martín the Human, the town of Nules was a place of refuge for the Centelles side; for this reason the King passed it to real jurisdiction, although for a short time.

It was Mr. de Nules who led the troops that, in the battle of Morvedre, defeated the supporters of Jaume d'Urgell, led by the governor of Valencia.

Chosen Fernando d'Antequera, in the commitment of Casp, the lords of Nules saw their influence and their political and economic power increase.

Nules was the general barracks of the royalist troops, but despite being one of the most fortified towns in the area, the troops had to move to Borriana, given that, as it had no moats, the town of Nules did not offer security.

In the middle of the sixteenth century, the Council of the town of Nules, together with those of Moncofa, Vila Vella and Mascarell, towns that formed the Barony of Nules, initiated a lawsuit against the counts of Oliva and lords of Nules, with the purpose of passing to real jurisdiction; which was achieved on September 24, 1582, with the royal sentence dictated by Felipe II and by which Nules became a royal town, appointing a royal court and justice that administered and held civil and criminal power throughout the Barony.

The Barony of Nules lost almost a third of its population and the tax burdens had to be borne by the residents of Nules and the new settlers. The losses that the Centelles suffered with the expulsion of the Moors were the excuse to return the Barony to the jurisdiction of its former lords, with the title of Marquess of Nules.

Nules was one of the few towns in the old Kingdom of Valencia that sided with the French pretender, enduring the occupation of the Bourbon army; for this reason Felipe V granted him the titles of Very Loyal and Fidelisima and the privilege of adding to the town's coat of arms a lion in a white field, an S and an L, and on the border that says: The Faithful and Loyal Village of Nules. Although the concession document is preserved in the Nules Historical Archive, the official coat of arms that the town has used since 1927 does not faithfully reflect this privilege.

Nules was attacked by the troops of General Suchet, who left a French garrison in the old hermitage of Sant Miquel (The Fort); during this contest, brother Asensi Nebot, guerrilla son of Nules, who the French nicknamed derogatorily with the name "La Fraila", played a very important role; he was the one who presided over the oath of allegiance to the Constitution of 1812 in Castelló, being forced, years later, to go into exile to defend constitutional freedoms against the absolutism of Ferdinand VII. Until the 19th century, Nules received the waters of the Millars through a common ditch with Borriana, this was the reason for continuous confrontations between the two towns. After long lawsuits, on September 6, 1878, the separation of waters was achieved, Nules being authorized to build its own sewer. This fact and the introduction of the first motor-pumps, as well as subscription imports and the prospects for export opened up by the "Transport Revolution"; he made it easy for the part of the area between the town and the mountains to be transformed into orange groves, at the same time that new horizons were opening up for the industrial development of the town.