The River Clyde (, , , or ) is a river that flows into the Firth of Clyde in Scotland. It is the ninth-longest river in the United Kingdom, and the third-longest in Scotland. It runs through the major city of Glasgow. Historically, it was important to the British Empire because of its role in shipbuilding and trade. To the Romans, it was , and in the early medieval Cumbric language, it was known as or . It was central to the Kingdom of Strathclyde (). Etymology The exact etymology of the river's name is unclear, though it is known that the name is ancient: It was called or by the Britons and by the Romans. It is therefore likely that the name comes from a Celtic language—most likely Old British. But there is more than one old Celtic word that the river's name could plausibly derive from. One possible root is the Common Brittonic , meaning 'loud' or 'loudly'. More likely, the river was named after a local Celtic goddess, Clōta. The goddess's name in turn derives from an older, Proto-Celtic word meaning 'the strongly flowing one' or 'the holy cleanser'. History Prehistory Humans have settled along the Clyde since the Paleolithic era. Artifacts dating from 12,000 BC have been found near Biggar, a rural town close to the river. Biggar is home to an archeological site at which Britain's most ancient artifacts have been unearthed. Prehistoric canoes, used by ancient peoples for transport or trade, have been found in the river. There are a number of Mesolithic sites along the Clyde, especially in the Upper Clyde Valley. Permanent settlements and structures, including what is believed to be a temple to moon gods in Govan, were constructed in the area during the Neolithic and Bronze Ages. Celtic art, language, and other aspects of culture began spreading to the area from the south during this period, and prehistoric artifacts suggest that, by around 1000 BCE, they had become the dominant cultural influences there. Ancient history Before the legions of the Roman Empire arrived in southern Scotland, the river and the area surrounding it had been settled by the Brythonic-speaking Damnonii tribe. It has been suggested that a Damnonii town called Cathures was located there and was the precursor to modern Glasgow. The Damnonii tribe originally distributed power among individual chiefdoms, but at some point before 500 AD the tribe politically