Founded between the 3rd and 4th centuries, it was restored in 1216 by
Pope Honorius III (some columns of his building survive in the present building's eastern apse); in 1582; in 1743 designed by
Giovanni Battista Nolli and in the 1750s reelaborated by Tommaso De Marchis (his main altar survives); and between 1852 and 1860 by the
Somaschi Fathers, who still serve it as a rectory church. The 16th century style façade, elaborated from the De Marchis phase, is built onto the medieval-style
quadriportico. The church has a
Romanesque campanile. On the south side of the nave is the funerary monument Eleonora Boncompagni
Borghese of 1693, to a design of Giovan Contini Batiste, and in the south transept the Chapel of
Charles IV of Spain, with the icon ''
Madonna di sant'Alessio'', an
Edessa icon of the
Intercession of the
Madonna dating from the 12-13th centuries, thought to have been painted by
St Luke the Evangelist and brought from the East by
St Alexius. The church also contains the tombstone of Peter
Savelli (of the same family as Pope Honorius III). In a Romanesque
crypt that survives below the church, the main altar contains relics of
St Thomas of Canterbury. The crypt's 12th-century wall of frescoes depicts the
Agnus Dei and symbols of the
Four Evangelists, and on the north aisle
St Gerolamo Emiliani introducing orphans to the Virgin by
Jean Francois De Troy, and at the end of the aisle
The Holy Steps and the titular church of Saint Alexius in wood and stucco by
Andrea Bergondi. Connected to the basilica are the buildings of the former
Benedictine monastery, which accepted the
Camaldolese reforms of
St. Romuald in the 10th century. The buildings now belong to the Italian state. In 2015, and again on 29 June 2019, the discovery of a medieval fresco in an exceptional state of preservation and integrity was noticed by the Italian press. The painting has been restored and its subject has been identified by the Italian art historian Claudia Viggiani with Christ the Pilgrim. The fresco was firstly discovered in 1965 by the Italian Genio Civile during the stabilization's works of the bell tower, and then discarded for forty years, until 2005.
Burials •
Giovanni Vincenzo Gonzaga == Cardinal title ==