Germania Superior was an imperial province of the Roman Empire. It comprised an area of today's western Switzerland, the French Jura and Alsace regions, and southwestern Germany. Important cities were Besançon (Vesontio), Strasbourg (Argentoratum), Wiesbaden, and Germania Superior's capital, Mainz (Mogontiacum). It comprised the Middle Rhine, bordering on the Limes Germanicus, and on the Alpine province of Raetia to the south-east. Although it had been occupied militarily since the reign of Augustus, Germania Superior was not made into an official province until c. 85 AD.