Fontenelles Abbey was an Augustinian monastery in the former commune of Saint-André-d'Ornay. The abbey was founded in 1210 by local landowners Guillaume de Mauléon, seigneur of Talmont-Saint-Hilaire, and his wife Béatrice de Machecoul, lady of the manors of La Roche-sur-Yon and Luçon. The monastery was originally Benedictine but after a lawsuit broke out between the abbot of Fontenelles and the abbot of Marmoutier, a prestigious Benedictine monastery, the community became Augustinian, as a daughter house of the nearby Chancelade Abbey, in about 1224.
The church was damaged during the Hundred Years' War. In 1533 there were only 9 monks here. In 1562 during the Wars of Religion Protestants attacked the abbey, killing some of the monks, set it on fire and largely destroyed it. In particular they damaged the church to the extent that part of nave collapsed, leaving it permanently shortened, with a Greek cross floor plan. Protestants attacked it again in the 1620s but were forced to repair the damage. The monastery was restored from 1669 onwards by the canons of the Congrégation de France.
The abbey, by that time containing only three monks, was suppressed during the French Revolution in 1791. In 1794 the passage of the 'infernal columns' through the Vendée left it entirely abandoned. The site was later used for agriculture: the church was turned into a barn and the abbot's lodging into accommodation for labourers. Continued neglect brought about the collapse of most of the remaining buildings including in 1935 the collapse of the south transept of what was left of the church. The site remains private property.
The monastery was built in granite in the Angevin Gothic style, transitional between Romanesque and Gothic. The truncated church is the most intact structure remaining, and contains the tomb of either the foundress Béatrice de Machecoul or her daughter Jeanne, Vicomtesse de Thouars, consisting of a recumbent effigy (gisant) in an arched recess (arcosolium) with small figures. There are also substantial remains of the chapter room but the rest of the former structures are in ruins.
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.