The Loire (French pronunciation: [lwaʁ]; Occitan: Léger; Breton: Liger) is the longest river in France and the 171st longest in the world. With a length of 1,012 kilometres (629 mi), it drains an area of 117,054 km2 (45,195 sq mi), or more than a fifth of France's land area, while its average discharge is only half that of the Rhône.
The human history of the Loire river valley begins with the Middle Palaeolithic period of 90–40 kya (thousand years ago), followed by modern humans (about 30 kya), succeeded by the Neolithic period (6,000 to 4,500 BC), all of the recent Stone Age in Europe. Then came the Gauls, the historical tribes in the Loire during the Iron Age period 1500 to 500 BC; they used the Loire as a major riverine trading route by 600 BC, establishing trade with the Greeks on the Mediterranean coast. Gallic rule ended in the valley in 56 BC when Julius Caesar conquered the adjacent provinces for Rome. Christianity was introduced into this valley from the 3rd century AD, as missionaries (many later recognized as saints), converted the pagans. In this period, settlers established vineyards and began producing wines.
The Loire Valley has been called the "Garden of France" and is studded with over a thousand châteaux, each with distinct architectural embellishments covering a wide range of variations, from the early medieval to the late Renaissance periods. They were originally created as feudal strongholds, over centuries past, in the strategic divide between southern and northern France; now many are privately owned.
The name "Loire" comes from LatinLiger, which is itself a transcription of the native Gaulish (Celtic) name of the river. The Gaulish name comes from the Gaulish word liga, which means "silt, sediment, deposit, alluvium", a word that gave French lie, as in sur lie, which in turn gave English lees.
Liga comes from the Proto-Indo-European root *legʰ-, meaning "to lie, lay" as in the Welsh word Lleyg which gave many words in English, such as to lie, to lay, ledge, law, etc.