The town has a major harbour on the right bank of the Loire estuary , near the Atlantic Ocean. Given its location, Saint-Nazaire has a long tradition of fishing and shipbuilding. Saint-Nazaire was a small village until the Industrial Revolution but became a large town in the second half of the 19th century, thanks to the construction of railways and the growth of the seaport.
Saint-Nazaire progressively replaced upstream Nantes as the main haven on the Loire estuary. As a major submarine base for the Kriegsmarine , Saint-Nazaire was subject to a successful British raid in and was heavily bombed by the Allies until Being one of the Atlantic pockets , Saint-Nazaire was one of the last territories in Europe to be liberated from German occupation, on 11 May Archaeologists believe that Saint-Nazaire is built upon the remnants of Corbilo , an Armorican Gaulish city populated by the Namnetes tribe, which according to the Greek navigator Pytheas was the second-largest Gaulish city, after Massilia now Marseille.
According to the 15th-century chronicler Alain Bouchart , Brutus of Troy , the mythical ancestor of the Bretons, travelled to Saint-Nazaire to set foot upon the new homeland of his people. The farthest extent of the Breton language in the Loire region is Donges , to the east of Saint-Nazaire.
According to the late-6th-century writer Gregory of Tours , the Roman Church sheltered the remains of the martyr Nazarius in a local basilica. According to legend, the Breton chief Waroch II sent an emissary to seize these relics. The plot was foiled when the emissary fractured his skull upon the lintel of the church door.
Waroch, interpreting this as a miracle, was deterred and the village thenceforth took the name of Sanctus Nazarius de Sinuario. After this point, the history of Saint-Nazaire, like much of Europe during the Dark Ages, is not well documented. Like the whole of Brittany, Saint-Nazaire formed part of the Duchy of Brittany until , when it was annexed by France. In , a fort was built on the order of the governor of Brittany to protect the town, which by then had inhabitants.
