The Basilica dei Santi Bonifacio e(d) Alessio is a basilica, rectory church served by the Somaschans, on the Aventine Hill in Rome. It is dedicated to Saint Boniface of Tarsus and (originally only) Saint Alexius.
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 the 1750s by Tommaso De Marchis (his main altar survives), and between 1852 and 1860 by the Somaschi, which congregation still serves it as a rectory church. The 16th century style facade, 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. It is an Edessa icon of the Intercession of the Madonna, the Heavenly Mediatress dating from the 12-13th centuries, thought to have been painted by St Luke the Evangelist and brought from the East by St Alexius.
A Romanesque crypt survives below the church, whose main altar contains relics of St Thomas of Canterbury. It has a 12th-century wall of frescoes of the Agnus Dei and symbols of the Four Evangelists, along with one in the north aisle of 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 monastery, which now belong to the Italian state.
References:The Church of St Donatus name refers to Donatus of Zadar, who began construction on this church in the 9th century and ended it on the northeastern part of the Roman forum. It is the largest Pre-Romanesque building in Croatia.
The beginning of the building of the church was placed to the second half of the 8th century, and it is supposed to have been completed in the 9th century. The Zadar bishop and diplomat Donat (8th and 9th centuries) is credited with the building of the church. He led the representations of the Dalmatian cities to Constantinople and Charles the Great, which is why this church bears slight resemblance to Charlemagne's court chapels, especially the one in Aachen, and also to the Basilica of San Vitale in Ravenna. It belongs to the Pre-Romanesque architectural period.
The circular church, formerly domed, is 27 m high and is characterised by simplicity and technical primitivism.