The Collegiate Church of Santa María del Manzano, located in the town of Castrojeriz, is an outstanding Catholic temple of great historical and artistic value. Its construction began in 1214 under the patronage of Queen Berenguela of Castile, daughter of King Alfonso VIII and mother of Ferdinand III the Saint. This religious monument, which stands at the foot of the hill where the castle of Castrojeriz is located, was once a collegiate church, a rank that reflects its ecclesiastical importance in the region.

On April 25, 1974, the Collegiate Church of Santa María del Manzano was declared an Asset of Cultural Interest in the Monument category (RI-51-0003934). In 2015, the collegiate church was included in the "Retrospective Inventory - Associated Elements" of the Ways of St. James in Spain, during the extension of the French Way of St. James and the Northern Ways by UNESCO, which reinforces its relevance as part of the cultural heritage linked to the Jacobean route.

The origins of the Collegiate Church of Santa María del Manzano date back to early times, although the oldest documentation refers that in the 10th century Count Garcí Fernández granted privileges to the canons of the temple, allowing them to build towers and fortresses in Castrojeriz and equating them to the villain knights of the town. These rights and privileges, granted in 974, were later ratified by Ferdinand IV of Castile in 1299, during his minority, according to Enrique Flórez in his work España Sagrada.

In 1050, King García Sánchez III of Navarre linked the temple to the Monastery of San Millán de la Cogolla, changing its name to the Abbey of Santa María de Castro. However, when Navarre lost its influence over the Castilian lands, the collegiate church remained an exempt abbey until the reign of Alfonso VII, who subordinated it to the Cathedral of Burgos. Alfonso VII granted the abbot of Castrojeriz a position of dignity in the cathedral of Burgos, marking the beginning of a new era. Under Alfonso VIII, in 1173, the collegiate church was secularized, abandoning the rule of Saint Benedict and adapting to a new ecclesiastical order.

Between the end of the 15th century and the beginning of the 16th century, the collegiate church underwent several reforms that included the remodeling of the vaults and the construction of the rose window of the main door. During the 18th century, under the direction of the architect Juan de Sagarvinaga, a disciple of Ventura Rodríguez, significant reforms were made to the structure of the church, including the construction of the Chapel of the Virgen del Manzano, new sacristies, the count's crypt, a new apse, and the choir.

The main doorway of the Collegiate Church of Santa María del Manzano, in Gothic style, is located on the west façade and is conceived as a flared arch with multiple archivolts decorated with vegetal motifs. On both sides of the arch are two 13th century stone statues representing the Virgin Mary and the Archangel Gabriel, both covered by decorative canopies. The Gothic rose window of the portal, recently restored, shows God in an attitude of blessing, surrounded by the apostles, together with the symbols of the four evangelists, angels and the donor's coat of arms.

On the south façade, the Renaissance façade contrasts with the Romanesque base of the bell tower, which was renovated in the 18th century when the bell tower was added in 1746. The original Romanesque apse was replaced by a rectangular chevet during the 18th century alterations.

The interior of the collegiate church, built mainly in Gothic style although with Romanesque traces, is characterized by its three-nave plan separated by late Romanesque former arches and covered with Gothic stone vaults. The central nave, higher and wider than the lateral ones, has five bays, providing a harmonious proportion and a feeling of spaciousness.

Among the most outstanding elements of the interior are the altarpieces, such as the 18th century main altarpiece, created under the patronage of the Counts of Ribadavia. This altarpiece contains several paintings depicting biblical scenes, including The Annunciation by Anton Rafael Mengs, and others attributed to his disciples, such as Mariano Salvador Maella and Francisco Bayeu. Also noteworthy are the choir stalls from 1776, the choir lectern and a neoclassical organ built around 1790. The choir loft houses a canvas of the Virgin of the Cherries, attributed to the Flemish painter Pieter Pourbus.

The chapel of Nuestra Señora del Manzano, built in the 18th century, houses the titular image, a polychrome stone sculpture of the Virgin Mary holding the Child Jesus. This image, dressed in a blue tunic and decorated with stars, is the object of great devotion and has been celebrated in several Cantigas de Santa Maria.

In the baptistery of the church is a Gothic tomb attributed to Queen Leonor of Castile, daughter of Ferdinand IV and sister of Alfonso XI. The queen was assassinated in 1359 by order of her nephew, Pedro I of Castile, and her tomb, which remained hidden behind an adobe wall until 1970, was discovered and attributed to Leonor because of its style and the female figure sculpted on the lid.

The Collegiate Church houses a small museum that exhibits objects related to Christian worship, such as wooden figures, some from the 14th century, paintings, books, chalices, and other religious items. This museum is especially oriented to pilgrims on the Camino de Santiago, who find in the collegiate church a place of rest and reflection.

The Collegiate Church of Santa María del Manzano is not only a monument of great architectural and artistic value, but also a symbol of the rich religious and cultural history of Castrojeriz and its importance on the Camino de Santiago. Its inclusion in the protected heritage reinforces its value as a place of interest and devotion for visitors and pilgrims who walk this historic Jacobean route.