The Basilica of Sts. Vitalis, Valeris, Gervase and Protase is commonly named Basilica di San Vitale. It was built in 400 with funds provided by Vestina, a wealthy dowager, and was consecrated by Pope Innocent I in 401/402. The dedication to St. Vitalis and his family (Saint Valeria, his wife, and Sts. Gervasius and Protasius, their sons) is dated to 412.
San Vitale was restored several times, the most important being the rebuilding by Pope Sixtus IV before the Jubilee of 1475, and then in 1598, 1938 and 1960. The church is currently located several metres under the level of the street (via Nazionale), that it faces.
The portico is the most ancient part of the church, possibly dating back to the 5th century. It was altered at the end of the 16th century. The inscription on the portico, with the arms of Pope Sixtus IV, dates from this time. Pope Pius IX built the staircase to the 5th century portico in 1859.
The church has a single nave, with walls frescoed with scenes of martyrdom, among which a Martyrdom of St Ignatius of Antioch, in which a ruined Colosseum is depicted. The apsis, original of the 5th century, is decorated with a fresco by Andrea Commodi, The Ascent to Calvary.
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.