Under the current Santa María La Antigua church foundations have been found remains of a Roman hypocaustum. The church was likely founded in 1095 by Count Pedro Ansúrez, although there are no remains of this original structure. The oldest parts of the current temple date to the late 12th century: the gallery in the northern side of the building and the tower, both in Romanesque style. The tower, one of the symbols of Valladolid, has four floors, the upper three featuring windows, and a pyramidal top.
The naves and sanctuary of the church were rebuilt in the 14th century in Gothic style, following the style of Burgos Cathedral. The church has three aisles, with three polygonal apses and a transept. The nave and the aisles are rib vaulted.
Due to a poor foundation, too next to the Esgueva River, and the increasing size of the parish population, the building underwent successive additions and reparations: in the mid-16th century, architect Rodrigo Gil de Hontañón restored the collapsing building, adding buttresses and several windows.
Also from this period date the high altar retablo, by Juan de Juni (1550-1562; now in the Valladolid Cathedral). Several Baroque altarpieces were executed for the church's interior during the 17th and 18th centuries, hiding the original Gothic appearance.
In the early 20th century the building was extensively restored and rebuilt in order to show its original Romanesque-Gothic appearance, following the doctrines of the French architect Eugène Emmanuel Viollet-le-Duc.
References:The Church of St Donatus name refers to Donatus of Zadar, who began construction on this church in the 9th century and ended it on the northeastern part of the Roman forum. It is the largest Pre-Romanesque building in Croatia.
The beginning of the building of the church was placed to the second half of the 8th century, and it is supposed to have been completed in the 9th century. The Zadar bishop and diplomat Donat (8th and 9th centuries) is credited with the building of the church. He led the representations of the Dalmatian cities to Constantinople and Charles the Great, which is why this church bears slight resemblance to Charlemagne's court chapels, especially the one in Aachen, and also to the Basilica of San Vitale in Ravenna. It belongs to the Pre-Romanesque architectural period.
The circular church, formerly domed, is 27 m high and is characterised by simplicity and technical primitivism.