Founded in the 10th Century, La Rochelle was made a free port by Guillaume X, Duke of Aquitaine, in 1137. It was France's largest harbour on the Atlantic coast until the 15th century, dealing mainly in wine and salt. From 1568, it became a Huguenot stronghold, and a period of prosperity followed until the 1620s. Then a conflict arose with King Louis XIII, and Cardinal Richelieu besieged the city. La Rochelle resisted for 14 months but was starved into surrender, and its privileges were revoked. Louis XIV issued the Edict of Fontainebleau, revoking the rights that had been granted to the Huguenots under the Edict of Nantes, and declaring Protestantism illegal. The persecution forced many Huguenots to emigrate to the New World.

Another period of prosperity ensued, La Rochelle traded actively with Canada, Africa and the Antilles. Trade waned during the French Revolution and the Napoleonic Wars, and the city lost its prominence. In 1864, La Rochelle was the site of the first diving experiments of the world's first mechanically powered submarine, the Plongeur, under the command of Marie-Joseph Camille Doré who was born in La Rochelle. Germany established a submarine base at the city's deep-water harbour, La Pallice, during World War II. La Rochelle was the last French city to be liberated at the end of the war. The submarine base still stands and has been used as a set for several movies.

Today, La Rochelle is a well equipped commercial harbour housing a sizable fishing fleet. Les Minimes is the largest pleasure boat marina in France, with a capacity of about 3,500 boats. La Rochelle has a strong boat-building industry. The Maritime Museum displays Jacques-Yves Cousteau's boat Calypso.