The Church de San Andrés is located on the site of a former church from the times of Moorish occupation. The former church had been frequented as a parish church by the patron saint of Madrid, San Isidro Labrador, and his wife Santa María de la Cabeza, who lived nearby.
The adjacent chapel of San Isidro was built at the site of the saint's house. Its construction began in 1657, after the saint was canonized in 1622. Further reconstructions were performed in 1663 and 1669, and later in 1783 and 1789. The initial construction in Baroque style was fashioned by José de Villarreal, and later Pedro de la Torre and Juan de Lobera. Much of the internal decoration, including paintings, were destroyed during the Spanish Civil War.
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.