They were prestigious as well as defensive works that have guarded the entrance to the harbour since the late 19th century.

They were crucial in protecting the city in case of hostile landing. Louis XIII kept them when he had the fortifications destroyed after the siege of La Rochelle.

With time the towers were put to different uses. Firstly, they were lodgings for ‘captains’ who were to watch vessel movements in the harbour and levy the fees and charges they had to pay. Then, during the Protestant era, the blue and white flag – the city’s colours – flew on the Chaîne Tower.  The coffin of François d’Andelot who had died in Saintes, was left there from 1569 to 1579, as well as that of René II de Rohan (from 1586 to 1599), Catherine de Parthenay’s husband who died in La Rochelle.

After the revocation of the Edict of Nantes in 1685, the Saint Nicolas Tower was used as a prison for ‘stubborn’ Protestants. Jean Migault, who had tried to escape from France, Nicolas, Sieur de Voutron et de Coureilles, who could not be forced to recant despite the presence of Dragons in his house, and also the owners of the Vaugouin and Pampin dwellings accused of hiding would-be fleeing religionists, were jailed there for various periods of time.