The basilica of Saint-Pierre-aux-Nonnains in Metz, France, is one of the oldest churches in Europe.

The building began life in the 4th century when Metz was an important Gallo-Roman city.

[1] The building belonged to one of several thermae (public baths complexes) which existed in Metz in Roman times.

In the 7th century, the structure was converted into a church, becoming the chapel of a Benedictine nunnery.

In the 16th century Metz was besieged by the troops of Charles V and later was converted into an important garrison town by the French.