The church of St. Gregory of Tesson dates, in its core, from the 12th and perhaps the 11th century, but what remains of the visible parts dates from the 13th century, with alterations in the 14th and 15th centuries. The current bell tower was built around 1880 in a Romanesque-Gothic style, where the abundance of pinnacles, awning windows, canted corners, and balustrades replace the absent archaeological interest. It rises on the side of the nave, in the west corner of the left transept.
This building, dedicated to Saint Gregory, is built on a classical plan, with a single nave, a transept with apses, a choir, and a semicircular apse. The façade, in pure Saintonge style and with its beautiful lines, includes a vast semicircular portal flanked by two blind bays, a gallery on the first floor, and a gable. The gallery arches no longer exist; When the gable was built in the 18th century, they were removed.
This façade, framed by tall, separate columns, is unfortunately obstructed, like too many churches today, by trees planted at the time of the suppression of cemeteries. These trees now obscure, here a façade, there an apse, elsewhere an interesting detail. Municipalities, aware of the honor of having such works of art on their land, should not only maintain them, but also clear them and strive to highlight them.
The five arches of the portal, simply adorned with a string of diamond points, rest on columns raised on a bench. Above, unarced columns, single or double, surmounted by crocketed capitals, have very wide abacuses that form as many consoles. At each end of the solid gable wall, topped by a cross with an escutcheon, stands a statue. One did not escape mutilation.
The nave has two vaulted bays with crossed ogival arches with three tori which, with the formerets, rest on two strong columns and two smaller ones topped with crocketed or foliate capitals. The smaller ones support lateral arches, each framing a semicircular window. At the top of the walls, curious little oculi of an unusual design also open—a rare detail in Saintonge; one is shaped like a crescent and fits within a circumference; another imitates a four-leaf clover. These openings were added at the time of the vaulting's restoration, that is, in the 14th century.
In the square of the transept, four blocks of eight columns are connected by pointed arches. This square, now vaulted like the bays of the nave, was originally covered by a dome surmounted by the old bell tower, destroyed during the war against the English. Each side of this bell tower was adorned with two round-arched windows with stringcourses. The base of the first floor is still visible.
The voluminous columns that border the square transept are remarkable. The columns of varying sizes all have capitals whose ornamentation of acanthus leaves or beaded garlands extends onto the flats of the pilasters in a frieze form. This very fine and meticulous decoration produces, despite numerous mutilations, a great artistic effect.
The very deep transept gives the whole the shape of a Greek cross. The transepts, vaulted in a pointed barrel, are illuminated by round-arched windows. The apse of the one on the left features two curious small capitals that surmount the small columns of the entrance arch. Their large, well-crafted abacuses extend into a beautifully sculpted cordon around the entire half-circumference and extend into a miter, supporting the base of the semi-domed vault.
This apse is externally adorned with four groups of two slender, twin columns forming light buttresses.