Thiene Cathedral replaced a previous church of the Assumption which apparently dated from before 1166. Construction was completed by 1314. It was rebuilt in 1625, and was substantially altered in the late 18th century by architect Ottone Calderari. The dome was not added till the 1930s. The nave ceiling is decorated with 15 paintings by Baroque Venetian painters, including Giulio Carpioni and Giovanni Battista Pittoni.
Next to the church is the tall obelisk-like bell tower, designed by Sebastiano Serlio, beyond which is the Church of the Rosary built in 1685 in a staid Baroque style. This church contains stucco and painted decorations by the local artists Ballante (1657-1729) and Valentino Bassi (17th century). The main altarpiece was painted in 1590 by Matteo Grazioli. The painting of the Annunciation in the north aisle was painted by the school of Alessandro Maganza (1509-1589). There are some ancient frescos, restored in the 1700s, of the 'Madonna delle Grazie' and a marble statue of Saint Joseph by Orazio Marinali.
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.