The Basilica di San Zeno name rests partly on its architecture and partly upon the tradition that its crypt was the place of the marriage of Shakespeare's Romeo and Juliet. It stands adjacent to a Benedictine abbey, both dedicated to St Zeno of Verona.
St. Zeno died in 380. According to legend, at a site above his tomb along the Via Gallica, the first small church was erected by Theodoric the Great, king of the Ostrogoths. Erection of the present basilica and associated monastery began in the 9th century, when Bishop Ratoldus and King Pepin of Italy attended the translation of the saint's relics into the new church. This edifice was damaged or destroyed by a Magyar invasion in the early 10th-century, at which time Zeno's body was moved to the Cathedral of Santa Maria Matricolare: on May 21, 921, it was returned to its original site in the crypt of the present church. In 967, a new Romanesque edifice was built by Bishop Raterius, with the patronage of Otto I, Holy Roman Emperor.
On January 3, 1117, the church, along with most of the city, was damaged by an earthquake; the church was restored and enlarged in 1138. Work was completed in 1398 with the reconstruction of the roof and of the Gothic-style apse.
Attached to the basilica is an abbey was erected in the 9th century over a pre-existing monastery. Of the original structure, destroyed in the Napoleonic Wars, only a large brick tower and the cloisters survive. It had originally another tower and the abbot's palace. For long time the abbey was the city's official residence of the Holy Roman Emperors. In the 1980s a restoration discovered frescoes from the 12th to 15th centuries.
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.