The church, built in the shape of a Latin cross, the first construction elements of which date from the 11th and 12th centuries, with later additions and alterations (15th and 19th centuries to the beginning of the 13th century then modified in the 15th and 16th centuries, is dedicated to Saint Séverin, alias Seurin, bishop of Bordeaux in the 5th century, and whose feast day takes place on October 21. However, the solemn patronal feast is that of Saint Blaise, martyr bishop of the 4th century, fixed on February 3, and for which there is great veneration in the country.
The main portal of the church, as well as the two false doors, are crowned by ogival arcades with a few rare ornaments borrowed from the Romanesque period, such as saw teeth, diamond points, etc. These gantries have been the subject of a subconstruction.
The nave is made up of three recently vaulted bays in brick and plaster, without ribs; each span is separated by groups of four small columns, only two meters and fifty high, and appearing to date from the 14th century. The apse has two bays in the 15th century ogival style.
The Saint-Joseph chapel, to the north, has kept its original Romanesque style; it is dominated by a semi-circular vault, and offers the example of an apsidion of which no advantage is currently being taken. It is adorned with a small apse which housed the baptismal font. The chapel of the Virgin, to the south, was remodeled in the 17th century; it has the character of a 15th century restorer; it was then lengthened, and consists of three spans. There is, it is said, an ossuary under the choir.
The bell tower with a cone or "pine cone" spire, placed above the transept, and about 24 meters high (54 steps lead to its summit), is worthy of attention. This is the oldest part of the church. It is covered with a stone dome carved in tortoiseshell called the pine cone bell tower, similar examples of which can be found in Saintonge (Abbaye aux Dames de Saintes, Notre-Dame-de-l'Assomption church in Fenioux)3 but which recalls above all the domes of Byzantine inspiration observed in Poitou, Angoumois and Périgord (church of N.-D.-la-Grande in Poitiers, cathedral of Saint-Pierre in Angoulême, cathedral of Saint-Front in Périgueux). The foreground includes five Romanesque windows on each side, oriented as usual, on the upper level there are only two; the tower ends in a cut of stone, formed of small somewhat deformed cubes and forming a slightly rounded cone, but deformed by time. Inside, this bell tower offers a quadrangular vault, with cut sides, of very good taste. The bell, weighing 430 kilograms, was cast by Guillaume Besson, from Angers, and blessed in 1859, under the name of Marie. The godfather was Mr. Blanc Fontenille, former lawyer and notary, mayor of Nieul, and the godmother Mrs. Marie Belloteau, born Babin; parish priest M.Antoine Lanson.