The baptistery of St. John the Baptist in Poitiers is one of the oldest religious monuments in France, which dates back to the period of very early Christianity. The first building was erected in the middle of the 4th century on the remains of Roman buildings, Future changes in the structure were made in the era of the Merovingians, so the baptistery is also referred to as an outstanding monument of architecture of that time.

The initiator of the construction of the baptistery was St. Hilary, the first Bishop of Poitiers.

Construction started in the year 360, and later the building grew to it’s current size. In the 6th century in the baptistery the pool was built for baptism by full immersion, a ritual adhered to at the time. But already in the 10th century the pool was filled up, instead, it appeared the font had changed and also the ritual itself. The bowl of the pool was discovered during excavations in the 20th century and helped scientists to determine the exact age of the entire structure. In the 10th century the building of the baptistery was also extended and rebuilt.

It contains the stone sarcophagus of the 5th to 7th centuries, as well as fragments of Roman buildings, found during excavations, and religious utensils.

The facade of the building is interesting as an example of the Merovingian style of art, the decorations used are marble, stucco, and elements of ancient architecture pediment, pilasters, capitals.
____________________________________

Fréjus Cathedral (French: Cathédrale Saint-Léonce de Fréjus) is a church located in the town of Fréjus in the Var department of Provence, in South East France, and dedicated to Saint Leontius of Fréjus.

The cathedral was the seat of the Bishop of Fréjus from the 5th century.

The church is part of a complex of a larger fortified complex of medieval religious buildings dating from between the 5th and 13th centuries, when Fréjus was an important religious and commercial centre of Provence, comprising a parish church and a cathedral under one roof; a baptistery; the bishop’s residence; a canonry, for the community of priests who served under the bishop; and a cloister.

The baptistery of the cathedral is a fine example of Merovingian architecture. It was built in the 5th century but hidden during later reconstruction, and was rediscovered in 1925 by French architect Jules Formigé. It is considered the oldest Christian structure in Provence, and one of the oldest in France.
__________________________________________________

Venasque

In the Romanesque era, a wall flanked by three semi-circular towers was built to reinforce the site’s natural defences and protect it from attack, which could only come from the southeast.

Under the Merovingian dynasty, the bishopric of Carpentras withdrew to Venasque due to the turmoil in the region. Saint-Siffredi, one of the bishops, is believed to be responsible for the construction of a cathedral and of a church dedicated to St John the Baptist, of which today no vestiges remain.

___________________________________________

Grenoble

The old church of St. Laurent in Grenoble dates back to the 4th Century and contains a Merovingian Crypt.