Proper noun
Raetia
(historical) A Roman province bordered on the west by the Helvetii, on the east by Noricum, on the north by Vindelicia, on the west by Cisalpine Gaul and on south by Italy, which occupied the region which is today central and eastern Switzerland, southern Bavaria, most of Tirol and part of Lombardy.
Diocletian invaded Germania through Raetia while Maximian progressed from Mainz. Source: Internet
As the fabric of the Roman Empire crumbled, the ability of Raetia, Noricum and Pannonia to defend themselves became increasingly problematic. Source: Internet
He was one of Rome's greatest generals, conquering Pannonia, Dalmatia, Raetia, and temporarily Germania; laying the foundations for the northern frontier. Source: Internet
Julian then divided his forces, sending one column to Raetia, one to northern Italy and the third he led down the Danube on boats. Source: Internet
The armies of Gaul, Brittania and Raetia sided with them shortly afterwards. Source: Internet