This shrine was built in the late 15th century. It is a Mudejar-style building, with a single nave and a sail vault over the chancel. The Catholic Monarchs ordered it constructions and granted particular graces under the Royal Decree of Graces signed in 1486 in Salamance.
Inside the temple is a burial mound with Visigoth inscriptions containing the venerable remains of the Holy Confessor Gregorio de Osset (6th century). He authored a treaty now lost, which defended the dogma of the Holy Trinity against the Arianism heresy.
Alongside other antiquities, such as a Roman cipo (2nd century BC) dedicated to Dasumia Turpila, the shrine is home to a magnificent mural painting (c. 1500) representing Saint Gregory the Great, in the so-called “Sevillian Primitive-style”.
There are two chapels on the left wall of the nave, one belonging to the Confraternity of the Vera Cruz, and the other to the Confraternity of the Soledad. The titular images are worshipped here.
San Gregorio de Osset (probably Alcalá del Río, 5th century-Alcalá del Río, 8 September 544), also known as San Gregorio Osetano and San Gregorio Bético was renowned for his defence of Catholicism.
Osset (nowadays, San Juan de Aznalfarache) was the capital of Visigothic Hispania. San Gregorio wrote the book ‘De Trinitate’ against Arianism and dedicated it to Gala Placidia Augusta. He lived to be sixty or seventy years old.
He was canonised in 560 by the Sevillian archbishop, the successor of Saint Laureano, for his defence of the Faith.
He was buried in the shrine to San Gregorio in Alcalá del Río, where he is highly venerated. Miracles have been attributed to the intercession of this saint.
The devotion to this saint dwindled with the Muslim invasion in the 8th century. His tomb was rediscovered here after the Spanish Reconquista of the town in 1245.
He is the patron saint of Alcalá del Río, and his festivity is on 9 September.