The church, under the name of St-Pierre and St-Paul, evolved according to its time. It bears the traces of the construction of the 12th century, a third of the building is from the 14th century, then it is enlarged in the 15th century with a spacious choir and the rest of the building is from the 16th century. The style is predominantly Gothic. Surmounted by an elevated tower in place of a bell tower, this tower, about 33 meters high, dates from 1790. Napoleon probably made his first communion in the church of Brienne. Before 1914, the chevet was surrounded by the cemetery. In 1940, the church was partially destroyed. It has remarkable stained glass windows, in particular the martyr of Sainte-Agathe and Noah’s ark, made in Troyenne grisaille. Free visit every day. It is possible to visit it with a guide during guided tours of Brienne-le-Château by the Tourist Office.