Later it took the party of the Infants of Aragón against Pedro I of Castile and was residence of Aragonese queen Leonor with his children in year 1354. It says the oral tradition that this queen lodged in the building known as " the Palace ", that until recently was used as a grain warehouse.

In the book of the Behetrías it is said that the village was property of Countesses Juana and Blanca, and that belonged to the "merindad" of Campos.

Queen Juana Manuel, wife of Enrique II of Castile, had founded the Hospital of Villafranca Montes de Oca (in Burgos province). In 1380 she gave to the hospital the villages of Villafranca, Torrelobatón and Tamariz de Campos, as a manor. She put the solely condition that this came about at her death, because the queen would continue using it. In 1392 the "provisora" Beatriz Martínez gave Torrelobatón and Tamariz de Campos to Alfonso Enríquez, who gave in exchange the manor of Villaharta, in the diocese of Calahorra, and an annual right of perpetual ownership of 1000 florins on alcabalas of the city of Burgos.

In the case of Tamariz, the organization of the council had her first development under the auspices of a manor, since from at least 1160 it belonged to the house of Lara. The repercussions of this early fact can be verified, for example, at fiscal level, because the village secularly paid two thirds of the "diezmos" to the manor. When in 1407 Salamón Maymón, renter of the royal thirds ("tercias reales") of the arciprestazgo of Castromocho asked for them in Tamariz, the council refused to the payment, presenting opportune writings and alluding to that the manor received - not only the traditional two ninth (2/9) parts that constituted the royal thirds but the 6/9 (the royal thirds are a rate that is extracted of the ecclesiastical "diezmo" and that mean the 2/9 of these habitually). According to a figure in a book of the Cathedral of Palencia in 1573 the Admiral perceives in all the places of his manor that belong to the bishop of Palencia the thirds, with the exception of Tamariz, where he receives the 6/9.

The years of greater splendor happened when the temple of San Juan was built, in the first half of century XVI.

It existed in Tamariz up to 9 brotherhoods, that is to say:

of San Juan: disappeared in 1618.

of San Pedro and San Andrés: disappeared in 1618.

of San Antonio Abbot: it was in the church of San Juan.

of Souls ("Ánimas")

of the Santísimo: it existed already in century XVI and has persisted until half-full of s. XX.

of the Holy Cross ("Santa Vera Cruz"): it was owner of the hermitage of the Humilladero.

of Holy Name of Jesus

of the Virgin of the Rosary: it was in the church of San Juan.

of Our Lady of the Castle: the only one that exists presently.

Until the end of the last century existed two parishes, San Juan and San Pedro. From the first one there are only left some walls, the rest of a white stone tower and a Renaissance gate of jónico style. The temple of San Pedro has a romanic gate of century XII and in its inner there are baroque altarpieces.

There were also several hermitages:

Hermitage of Our Lady of the Castle: of the brotherhood of the same name and the only one that today persists.

Hermitage of Our Lady of the Knoll: it was located at highest of the town, where today it is a corral of ewes; it disappeared at the beginning of XVII century.

Hermitage of San Antonio Abbot: it was property of this brotherhood.

Hermitage of San Pedro Villame: it corresponds to an uninhabited medieval place and it is between the Hermitage of the Virgin of the Castle and Tamariz.

Hermitage of San Bartholomew: it was at the right side of the way to Berrueces.

Hermitage of the Humilladero: it was property of the Brotherhood of the Vera Cruz, it was on the way to Belmonte, next to the bridge of the same name.

It also existed in Tamariz, as in almost every village, a hospital of medieval origin, whose purpose was to give manutención and temporary lodging to the numerous poor men who moved of one to another population. It exists in the "Archivo Diocesano de Valladolid" an Account Book of this hospital that begins in 1601 and ends in 1784, in which it can be followed some of the ups and downs of this institution.

Documents about the Hospital