Santa Maria Maggiore church is an example of First Romanesque art. It includes the oldest cross vaults in Italy.
The oldest document mentioning the basilica is a privilege by pope Paschal II, dated 22 August 1107. Archaeological studies showed that at least two churches existed in the site before the current one, the earliest one being perhaps contemporary to the annexed baptistery of San Giovanni ad Fontes (c. 5th-7th centuries). The basilica has a nave and two aisles with a lower transept. The façade was originally embedded in the city's walls, but later the first three bays were abandoned and a new façade was obtained by closing one of the internal arches with a new wall.
The nave is characterized by arches which, at the sides, have double mullioned windows at the sides. The pillars which do not support the arches are prolonged by blind columns up to the clerestory. The longitudinal arches (those separating the nave from the aisles) are supported by semicolumns which form the pillars. The aisles are a 14th-century reconstruction of the original ones. In 1944 a crypt, perhaps unfinished, was discovered.
Adejacent to the basilica is the nearly coeval Baptistery of San Giovanni ad Fontes.
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.