Nantes was identified during classical antiquity as a port on the Loire. It was the seat of a bishopric at the end of the Roman era before it was conquered by the Bretons in 851. Although Nantes was the primary residence of the 15th-century dukes of Brittany, Rennes became the provincial capital after the 1532 union of Brittany and France. During the 17th century, after the establishment of the French colonial empire, Nantes gradually became the largest port in France and was responsible for nearly half of the 18th-century French Atlantic slave trade. The French Revolution resulted in an economic decline, but Nantes developed robust industries after 1850 (chiefly in shipbuilding and food processing). Deindustrialisation in the second half of the 20th century spurred the city to adopt a service economy.
In 2020, the Globalization and World Cities Research Network ranked Nantes as a Gamma world city. It is the third-highest-ranking city in France, after Paris and Lyon. The Gamma category includes cities such as Algiers, Orlando, Porto, Turin and Leipzig. Nantes has been praised for its quality of life, and it received the European Green Capital Award in 2013. The European Commission noted the city's efforts to reduce air pollution and CO2 emissions, its high-quality and well-managed public transport system and its biodiversity, with 3,366 hectares (8,320 acres) of green space and several protected Natura 2000 areas.
Nantes is named after a tribe of Gaul, the Namnetes, who established a settlement between the end of the second century and the beginning of the first century BC on the north bank of the Loire near its confluence with the Erdre. The origin of the name "Namnetes" is uncertain, but is thought to come from the Gaulish root *nant- (river or stream, from the pre-Celtic root *nanto, valley) or from Amnites, another tribal name possibly meaning "men of the river".
Its first recorded name was by the Greek writer Ptolemy, who referred to the settlement as Κονδηούινκον (Kondēoúinkon) and Κονδιούινκον (Kondioúinkon)[A]—which might be read as Κονδηούικον (Kondēoúikon)—in his treatise, Geography. The name was latinised during the Gallo-Roman period as Condevincum (the most common form), Condevicnum, Condivicnum and Condivincum. Although its origins are unclear, "Condevincum" seems to be related to the Gaulish word condate "confluence".
The Namnete root of the city's name was introduced at the end of the Roman period, when it became known as Portus Namnetum "port of the Namnetes" and civitas Namnetum "city of the Namnetes".Like other cities in the region (including Paris), its name was replaced during the fourth century with a Gaulish one; Lutetia became Paris (city of the Parisii), and Darioritum became Vannes (city of the Veneti). Nantes' name continued to evolve, becoming Nanetiæ and Namnetis during the fifth century and Nantes after the sixth, via syncope (suppression of the middle syllable).
