transportation. The port of Strasbourg is the second-largest on the Rhine after Duisburg in Germany, and the second-largest river port in France after Paris. Etymology and names Until the fifth century CE, the city was known as Argantorati (in the nominative, Argantorate in the locative), a Celtic Gaulish name Latinised first as Argentorate (with Gaulish locative ending, as appearing on the first Roman milestones in the first century CE) and then as Argentoratum (with regular Latin nominative ending, in later Latin texts). That Gaulish name is a compound of -rati, the Gaulish word for fortified enclosures, cognate to the Old Irish ráth (see ringfort) and arganto(n)- (cognate to Latin argentum, which gave modern French argent), the Gaulish word for silver, but also any precious metal, particularly gold, suggesting either a fortified enclosure located by a river gold mining site, or hoarding gold mined in the nearby rivers. After the fifth century CE the city became known by a completely different name, later Gallicized as Strasbourg (Lower Alsatian: Strossburi; ). That name is of Germanic origin and means 'town (at the crossing) of roads'. The modern Stras- is cognate with the German Straße and English street, both derived from Latin strata ("paved road"), while -bourg is cognate with the German Burg and English borough, both derived from Proto-Germanic *burgz ("hill fort, fortress"). Gregory of Tours was the first to mention the name change: in the tenth book of his History of the Franks written shortly after 590 he said that Egidius, Bishop of Reims, accused of plotting against King Childebert II of Austrasia in favor of his uncle King Chilperic I of Neustria, was tried by a synod of Austrasian bishops in Metz in November 590, found guilty and removed from the priesthood, then taken "ad Argentoratensem urbem, quam nunc Strateburgum vocant" ("to the city of Argentoratum, which they now call Strateburgus"), where he was exiled. Geography Location Strasbourg is situated at the eastern border of France with Germany. This border is formed by the Rhine, which also forms the eastern border of the modern city, facing across the river to the German town Kehl. The historic core of Strasbourg, however, lies on the Grande Île in the river Ill, which here flows parallel to, and roughly from, the Rhine. The natural courses of the two rivers eventually join some distance downstream of Strasbourg, although several artificial waterways now connect them