Corseul was called Fanum Martis ('Temple of Mars') in Latin and was the capital of the Gallo-Roman province of Coriosolites. It was founded in 10 BC. In the 3rd and 4th centuries, like many other cities, Fanum Martis was renamed for its people, the Curiosolitae. This name change occurred as the Roman Empire weakened and paralleled a revival of the ancient Gallic gods in local religious sculptures and dedicatory inscriptions.
Monterfil, today in Corseul city centre, was the antic city’s trading area and was built on a Roman grid plan. It was laid out around a 10m wide central street and two main perpendicular lanes delineating the blocks or insulae. It was developed in the 1st century BC and remained active until the 3rd century AD when it was burnt. The site has been transformed into an elegant public garden known as Jardin des Antiques.
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.