Raetia ( or , , also spelled Rhaetia) was a province of the Roman Empire, named after the Rhaetian (Raeti or Rhaeti) people. It bordered on the west with the country of the Helvetii, on the east with Noricum, on the north with Vindelicia, on the west with  Transalpine Gaul and on south with Venetia et Histria. It thus comprised the districts occupied in modern times by eastern and central Switzerland (containing the Upper Rhine and Lake Constance), southern Bavaria and the Upper Swabia, Vorarlberg, the greater part of Tirol, and part of Lombardy. Later Vindelicia (today south-eastern Wuerttemberg and south-western Bavaria) formed part of Raetia. The northern border of Raetia during the times of Augustus and Tiberius was the River Danube. Later the Limes Germanicus marked the northern boundary , stretching for 166 km north of the Danube. Raetia linked to Italy across the Alps over the Reschen Pass, by the Via Claudia Augusta. The Romansh people living in Southeast Switzerland are believed to be direct descendants of the Raetians. However, the exact lineage of the Romansh (or Romansch) people remains incomplete.