A church at the site of current San Francesco, dedicated to St John, was present since perhaps the seventh-century, since nearby Christian burial appear to date from then. In around 1244, the church began to be administered by priests from the Cathedral of Acqui. Around 1410, it became associated with the Franciscan order, and rebuilt and rededicated. The convent was suppressed in 1802, and the church was affiliated with the Confraternity of San Giuseppe, who briefly changed the name of the church. In 1824, the Franciscans returned, and they rebuilt the church in a neoclassic-style, adding the Facade, under the design of Ferraris in 1835, completed in 1854.
Parts of the church are ancient. The bell-tower and apse date to the 15th century. But other parts reflect refurbishments along the centuries, including the 19th-century reconstruction. The broad brick facade (1835–1854) shows eclectic styles with a triangular lower tympanum and monumental order pilasters.
The interior houses an Immaculate Conception by il Moncalvo; an Adoration of the Magi by Raffael Angelo Soleri; and a Madonna and Child with Saint Francis and Antony of Padua by Pietro Beccaria. The ceilings were frescoed by the 19th-century painter Pietro Ivaldi, detto il Muto di Toleto.
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.