Also stands out figures as the painter Francisco Javier Parcerisa, or the writer José de Espronceda, the generals Joseph Léopold Sigisbert Hugo and Arthur Wellesley, the Duke of Wellington, who set his garrison barracks in this castle during the Spanish War of Independence.

The walled enclosure already appears in documents from 1264, and it was Alfonso X the Wise who granted the council of Cuéllar the possibility of investing the proceeds of certain fines in its repair.

On 23 July 1433, John II granted the town of Cuéllar to Constable Álvaro de Luna, who swore an oath of homage to its inhabitants on 3 October of the same year.

It is possible that even then Álvaro de Luna began to plan the new fortress of Cuéllar, but he had little material time to carry it out: in 1439 he was banished from the court, and the lordship of the town was ceded by John II of Castile on 26 April of the same year to his namesake, the King of Navarre, who held it until 1444.

Henry IV, who felt a great predilection for Cuéllar, where he held the first Cortes of Castile of his reign in 1455, refused to accept his father's will, and persisted in managing the town personally, despite the fact that the manor belonged to his half-sister.

Thus, on 22 July 1462, he ordered Alfonso Pérez de Segovia to give him 20,000 maravedíes each year for the tenancy of the castle, and similar deeds were issued in 1463 and 1464.7 John II bequeathed the villa to Isabella in his will, and Henry, in order to take possession of it, had to pay his half-sister 200,000 "doblas de la Banda para su dote e casamiento" (doubloons of the band for her dowry and marriage).

Perhaps for this reason, the work he carried out on the castle was based on fortifying the existing building in order to defend it in the event of an attack by the Infanta Isabella.

... and I give, transfer and renounce it all to you, the said Duke of Alburquerque and to your heirs and successors.... Mª Rosario Mondéjar Manzanares[14]Beltrán de la Cueva went from fearing a possible attack by Isabella to being well regarded at her court.

He undoubtedly gained royal favour for having fought against the Portuguese defending the Queen's rights at the Battle of Toro on 1 March 1476, in the context of the War of the Castilian Succession.

Because of its geographical location, halfway between Segovia and Valladolid, and the existence of the castle, the Villa played a role of some importance during the War of Independence, and the fortress a place coveted by the French.

The parish priest of the municipality, a witness and reporter, had to shelter an English captain and his wife, and claims that Wellington rode past, "smilingly reciprocating the greetings of the crowd".

They were looked after by the population with abundant food, good bedding and fodder, but in view of the danger of the guerrillas, they left Cuéllar in the direction of Tudela de Duero.