Then the first urban expansion of the population takes place, which breaks longitudinally towards the Southwest with its old walled structure. Along this axis rise the Pósito, seat of the Town Hall, and the church of Ntra. Sra. De la Concepción, a parish standing until 1955, the year in which the current one was built on it, losing the population one of the two historic parishes that it had in the past. The other parish stands ruinous within the lower enclosure of the fortress, configuring with it and the splendid nature of the Sierra that frames it one of the most beautiful places in the province of Jaén. This second temple, dedicated to Santo Domingo, is the result of the efforts of one of the most influential men in the Spain of Carlos I, the famous and arrogant secretary Francisco de los Cobos, who managed to take over the lordship of the Advancement in 1534, remaining under the administration and control of its descendants, the Marquises of Camarasa, until 1606, when it was recovered by the Archbishopric of Toledo, owner of the vast estate since the 13th century. During this period, what Rus Puerta qualifies as Iglesia Mayor would be built. But this monumental temple presented a certain abandonment and ruin in the 18th century.

In the Cadastre of the Marqués de la Ensenada, of 1751, the state in which it was found is thus related: “(...) what causes the greatest pain is seeing the factory of the greater parish of Santo Domingo de SIlos to be finished, being it is quite decent, and because of the many harassments and roofs that it is with today, because it is not perfected it suffers the continuous detriment of such continuous expenses to be able to preserve itself (: ..) ”. The War of Independence caused its total ruin, as it was set on fire, like Santa María, de Cazorla, on July 4, 1810 by French troops. Later it was used as a cemetery until the middle of the 20th century, the remains of this occupation still being visible.

According to Vicente Salvatierra, it seems very possible that the original church could have been in the same location as that of Santo Domingo, at the foot of the castle. In the opinion of Luis Magaña, Rodrigo de Gibaja, a master stonemason linked to the Archdiocese of Toledo and responsible for the factories of the Colegial de Baeza and the church of Puebla de Don Fabrique, in Granada, was in charge of the works of the churches from Santa María, in Quesada, and from Santo Domingo de La Iruela. The participation of the Cazorlan stonemason Gabriel de Tauste has also been documented. There is no documentary evidence of the intervention of Andrés de Vandelvira, but it is very likely that he gave the plans at the request of Francisco de los Cobos around the year 1534, taking charge of the execution Gibaja and Tauste, among other master stonemasons.

Chueca Goitia, comparing the remains of the churches of Santa María, of Cazorla, with that of La Iruela, estimates that the latter "is of poorer and coarser art, as made by local masters following, surely, Vandelviresque inspirations." In any case, both factories are being built in parallel, the one in Cazorla expanding over time. Of that monumental temple, only part of the perimeter walls, the access portals, the spiral staircase to access the bell tower, the main and collateral chapels and a monumental portal on the side of the Gospel with a relief in which is It represents the miracle of the imposition of the chasuble to San Ildefonso. The plant had three naves and the head was flat and prominent.

Certain decorative features, the layout of the access doors and, above all, the composition of the elevation of the walls of the transept or first large section, articulated by a large semicircular arch in the upper part and two chapels in the lower part separated between if by a pilaster with a veined niche, they are clearly Vandelvian. In the cathedral of Jaén or in San Isidoro de Úbeda, Andrés de Vandelvira monumentally incorporated this composition, executed with greater simplicity in the case of La Iruela.