Construction of the old Comillas Seminary was begun in 1881, under the patronage of the successful fortune-seeker Antonio López del Piélago y López de la Madrid (1817-1883), first Marquis of Comillas. At his death in 1883, his son Claudio López Bru continued financing the building until it was completed in 1890.
The project was carried out by the Catalonian architect Joan Martorell i Montells (1833-1906), with the counsel of Father Alcolado, a Jesuit engineer, and Father Gómez Carral, member of the Jesuit order. Thus, the general layout of the building follows very traditional Jesuit guidelines, with two patios – the community patio and the classroom patio - separated by the church.
The location chosen for this magnificent work was not by chance, since it was the Marquis himself who decided to place it facing his Palace of Sobrellano. On-site construction was directed by the master Cristóbal Cascante y Colom. In 1889, Martorell personally recommended the architect Lluís Doménech i Montaner, to whom is owed the ornamental embellishment of the building. Other Catalonian artists took part, such as the painter Eduard Llorens Masdeu and the Masriera & Campins foundry (Bronze Doors of Virtues).
The materials used in the construction of the building’s facades are a combination of masonry and brick work, interspersed with ceramic tiles in the Medieval and Renaissance traditions. The portico of the seminary is nothing less than the doorway to a world completely different from the world on the outside. The decorated floor, the slim arches and columns and the woodwork of the stairway, with the complex intertwining of cornices, columns, pendants and fleurons all work in conjunction to transform the interior. This vestibule allows the visitor to admire how the various areas are separated by columns, light and chromatic nuances.
The large room over the vestibule houses a large frieze painted by Llorens with images from the Old and New Testaments, looking over a wooden balustraded gallery.
The monumental gate of the Seminary pictures the arms of the Holy See and the monogram of the Society of Jesus held by two pages that includes the date "1890" in reference to Leo XIII, owner of the building at that time and “1892”, date of the inauguration of studies in the Seminary.