Having travelled by ship to Massilia and then up the Rhône (see here), Hadrian’s route towards the German frontier will certainly have been along the Via Agrippa, the main Roman road from the Mediterranean to the Rhine.
From there, Hadrian was to implement his new military policy of defensive imperialism. A passage in Dio Cassius describing Hadrian bareheaded in the “German snows” (Dio 69.9.4) plausibly refers to his wintering with the troops at the garrisons in Germany in 121/2. His first intended destination was the German frontier ( limes ) which he probably reached in the autumn or winter of that year. In the year AD 121, Hadrian left Rome and set off on an ambitious tour of the western provinces.
