The Basilica della Collegiata was built in the early 18th century, after the earthquake of 1693 that had destroyed most of the city.
The design of the church is attributed to Angelo Italia (1628–1700), who changed the orientation of the previous edifice destroyed by the earthquake, in order to have it facing the new via Uzeda (current Etnea Street) according to the rebuilding plan of the city. The façade, designed by the polish architecte Stefano Ittar (1724–1790), is one of the most notable examples of late Baroque in Catania.
It has two orders, the first of which featuring six stone columns, surmounted by a balustrade. The second order has a large central window, with, at the sides, four large statues of St. Peter, St. Paul, St. Agatha and St. Apollonia. Over the second floor is a central element housing the bells.
The church is accessed through a large staircase on which, delimiting the parvise, is a wrought iron parapet.
The interior follows a common basilica plan, with a nave and two aisles divided by two pilasters, and three apses. The central apse is rather elongated to house the rectory.
The right aisle is home to a baptistery and three altars with canvasses of saints. At the end of the aisles is the Immaculate altar, preceded by a marble balaustrade, over which is a marble statue of the Madonna. In the apse of the nave is the high altar, with an icon of the Virgin with a Child, a copy of a Byzantine original in the sanctuary of Biancavilla. Behind the altar are an 18th-century wooden organ and a wooden choir.
The left aisle, in the apse area, houses the Holy Sacrament Chapel, with a marble altar. The vaults and the dome were frescoed in 1896 by Giuseppe Sciuti with scenes of the Life of Mary, Angels and Saints.
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.