The Quadi were an early Germanic people who lived approximately in the area of modern Moravia in the time of the Roman Empire. The only known information about the Germanic tribe the Romans called the 'Quadi' comes through reports of the Romans themselves, whose empire had its border on the River Danube just to the south of the Quadi. They associated the Quadi with their neighbours the Marcomanni, and described both groups as having entered the region after the Celtic Boii had left it deserted. The Quadi are thought to have been an important part of the Suebian group who crossed the Rhine with the Vandals and Alans in the 406 Crossing of the Rhine, and later founded a kingdom in northwestern Iberia.