Originally founded as a town by the Gallic tribe named Namnèti around 70 BC, Nantes was conquered by Julius Caesar in 56 BC and named Portus Namnetus. Christianised in the 3rd century AD, the city was successively invaded by the Saxons (around 285), the Franks (around 500), the Britons (in the 6th and 7th centuries) and the Normans, who laid it waste in 843: "The city of Nantes remained for many years deserted, devastated and overgrown with briars and thorns." The Chronicle of Nantes continues until the year 946, telling that Alain Barbe-Torte, grandson of Alan the Great, the last king of Brittany who was expelled by the Norse, drove them out and founded the Duchy of Brittany.
When the Duchy of Brittany was annexed by the kingdom of France in 1532, Nantes kept the Parliament of Brittany for a few years, before it was moved to Rennes. In 1598, King Henry IV of France signed the Edict of Nantes here, which granted Protestants rights to their religion.
During the 18th century, prior to abolition of slavery, Nantes was the slave trade capital of France. This kind of trade led Nantes to become the largest port in France and a wealthy city. When the French Revolution broke out, Nantes chose to be part of it, although the whole surrounding region soon degenerated into an open civil war against the new republic known as the War in the Vendée. On 29 June 1793 the town was the site of a Republican victory in this war. The Loire was the site of tens, perhaps hundreds of thousands of executions by drowning, including those using the method which came to be known as the Republican marriage, in which a man and a woman were stripped naked, tied together, and thrown into the river.
In the 19th century, Nantes became an industrial city. The first public transport anywhere may have been the omnibus service initiated in Nantes in 1826. It was soon imitated in Paris, London and New York. The first railways were built in 1851 and many industries were created. In 1940, the city was occupied by German troops. In 1941, the murder of a German officer, Lt. Col. Fritz Hotz, caused the retaliatory execution of 48 civilians. The city was twice severely bombed by British forces, on 16 and 23 August 1943, before being liberated by the Americans in 1944.
Until the 1970s, Nantes' harbour was located on the Île de Nantes, when it was moved to the very mouth of the Loire River, at Saint-Nazaire. In the subsequent 20 years, many service sector organisations moved into the area, but economic difficulties forced most of these to close. In 2001, a major redevelopment scheme was launched, the goal of which is to revitalise the
In 2003, the French weekly L'Express voted Nantes to be the "greenest city" in France, while in both 2003 and 2004 it was voted the "best place to live" by the weekly Le Point. In August 2004, Time designated Nantes as the "the most livable city in all of Europe".