The Asturian king Fruela I ordered the construction of a basilica consecrated to San Salvador on the site where the present-day cathedral of Oviedo stands today. The exact moment of the foundation is unknown, although thanks to one of the two foundation inscriptions of the cathedral of Alfonso II of Asturias the Chaste, the foundation of the church by Fruela I can be attested. Although these foundation inscriptions were destroyed at the beginning of the 16th century, the text was collected by Bishop Pelayo in the Liber Testamentorum Ecclesiae Ovetensis or Book of Testaments.
King Alfonso II the Chaste, on transferring the capital of the Kingdom of Asturias to Oviedo, ordered the construction of a cathedral complex on the same land, taking advantage of some of the spaces of the old church of San Salvador, a complex that corresponds to the urban planning scheme of the High Middle Ages: a double cathedral, i.e., unique in its institutional conception, but consisting of two buildings with different uses, the bishop's residence, episcopal quarters and a defence wall.
The Crónica Silense gives an account of the thirty-year construction of the ecclesiastical complex, which also included the Church of San Tirso, confirming the existence of an ambitious long-term construction project.
The complex of churches was made up of several buildings of worship of which we have some documentary references, the monastery of San Vicente, the later one of San Juan Bautista and San Pelayo and, as the main nucleus, the basilicas of San Salvador and Santa María, which remained standing until the 18th century, annexed to the previous one as a cemetery space. San Salvador was the main church and very possibly the king's "own church", while Santa María was dedicated to the funeral liturgy dedicated to Alfonso II and, later, to all the kings of Asturias. In fact, the aforementioned Benedictine monasteries of San Vicente (male) and San Juan Bautista and San Pelayo (female) also participated in the funeral liturgy in Santa María, as documented until the 16th century, when this authentic holy city disintegrated after the reconstruction of San Vicente and the change of location of its church and the subsequent segregation of San Pelayo into a strict female enclosure, closing the doors that connected both institutions with the cemetery of San Salvador, centred on the royal funeral chapel. 6 7 The basilica of San Salvador was probably consecrated on 13 October 821. It was a three-nave building with a triple rectangular chancel and a wooden roof, modelled on the church of Santullano. Its dimensions were approximately 40 m long, 20 m wide and 25 m high at most.8 The tripartite chevet housed a main altar dedicated to San Salvador, the patron saint of the church, and another twelve altars dedicated to the apostles, which later grew to twenty-one, many of them with a double dedication. The church would have been decorated with paintings in a similar style to those in Santullano.
To the south of San Salvador there were a series of constructions of which there are still remains today to the south of the cathedral and below the current Episcopal palace. Taking advantage of its total destruction during the Spanish Civil War and as part of the reconstruction work, excavations were carried out between 1942 and 1950. Archaeologists José María Fernández Buelta and Víctor Hevia Granda determined that they corresponded to the royal palace of Alfonso II the Chaste. However, this opinion is now rejected by other historians, such as César García de Castro Valdés and Eduardo Carrero Santamaría, who question the original location of the palace, while the remains next to the cathedral must have belonged to the clergy who took care of San Salvador until it was promoted to cathedral status, at which point they must have been transformed into the Bishop's palace and other episcopal quarters, at the same time as the houses and palaces of the chapter dignitaries were built in the surrounding area, which, to a large extent, survived topographically until the contemporary opening of the current Corrada del Obispo. 9 10 The Holy Chamber would therefore be the treasury of the cathedral of San Salvador, following the constants of the architecture of the time, made up of two superimposed spaces attached to a higher square structure called the Tower of San Miguel.11 There is no documentary evidence of the functioning of the lower floor, nicknamed the "crypt of Santa Leocadia", which served as a burial space at a somewhat later date than its construction, with the raising of a funerary portico on its north side. The upper one, the treasury itself, later known as the Chapel of San Miguel, acquired in the 11th century, once the cult of relics and pilgrimage had developed, the function of reliquary that it retains today. It is assumed that the construction of this building took place around 884, during the reign of Alfonso III the Great, together with the Old Tower which served as a defence and completed the fortification of the previously erected complex.
At the end of the 11th century, the Old Tower completed its defensive function with that of a bell tower, receiving for this purpose a Romanesque body with two openings in the façade with a semicircular vault.
More important is the reform carried out in the Holy Chamber at the end of the 12th century. The old wooden roof was dismantled to build a barrel vault that rests inside on columns on which an Apostleship was sculpted, a masterpiece of Spanish Romanesque art. The sculpted heads of Christ, Saint John and the Virgin were embedded in the west wall, and the rest of the scene was painted on the wall itself. The remains of the painting on this wall disappeared when the Holy Chamber was blown up during the Asturias Revolution of 1934, and so today the heads appear to be out of context.
The influence of Gothic architecture, which was already evident in Castile at the beginning of the 13th century, did not reach Asturias until the end of that century, when the Gothic renovation of the cathedral complex began, not in the main building, perhaps out of reverence for the old basilica or due to a lack of resources to undertake such a large-scale work, but in the annexed buildings: the chapter house and the cloister. It would be almost another century before the Gothic cathedral was begun.
The chapterhouse owes its construction to the patronage of the cathedral's chantre Pedro Esteban, who died in 1293 and was buried in the chapterhouse itself, and to that of the dean and later bishop Fernando Alfonso. Neither the architect responsible for the design and direction of the building's construction, nor its starting date are known. It is known that in 1300 they were already begun and that in March 1314 the first meeting of the cathedral chapter took place in the new hall.
The construction of the Gothic church began in 1382 under the mandate of Bishop Gutierre de Toledo. Juan de Badajoz el Viejo was chosen as the first architect, although Juan de Candamo de las Tablas and Pedro Bunyeres 1920 also worked on the transformation of the presbytery into a main chapel.
In the 16th century the portico and the tower of the façade were completed. This is what we can see of the cathedral today. In the following centuries, works and improvements were carried out in many of the chapels.
On 11 October 1934, during the burning of convents during the Asturias Revolution, a group of revolutionaries exploded a bomb in the crypt of the Holy Chamber that ruined a large part of the monument and caused serious damage to the structure. The works of art were also badly damaged and important relics were lost, although treasures such as the Holy Shroud could be rescued from the rubble. The reconstruction of this disaster was carried out between 1939 and 1942, respecting as far as possible and rebuilding according to the original.