Strabo Geography 4.6.9

[9] After these come certain of the Norici, and the Carni, who inhabit the country about the Adriatic Gulf and Aquileia. The Taurisci belong to the Norici. Tiberius and his brother Drusus in one summer put a stop to their lawless incursions, so that now for three and thirty years ¹ they have lived quietly and paid their tribute regularly. Throughout the whole region of the Alps there are hilly districts capable of excellent cultivation, and well situated valleys; but the greater part, especially the summits of the mountains inhabited by the robbers, are barren and unfruitful, both on account of the frost and the ruggedness of the land. On account of the want of food and other necessaries the mountaineers have sometimes been obliged to spare the inhabitants of the plains, that they might have some people to supply them; for these they have given them in exchange, resin, pitch, torches, wax, cheese, and honey, of which they have plenty. In the Mount Apennine ² which lies above the Carni there is a lake which runs out into the Isar, which river, after receiving another river, the Aude, ³ discharges itself into the Adriatic. From this lake there is also another river, the Atesinus, which flows into the Danube. ⁴ The Danube itself rises in the mountains which are split into many branches and numerous summits. For from Liguria to here the summits of the Alps stretch along continuously, presenting the appearance of one mountain; but after this they rise and fall in turns, forming numerous ridges and peaks. The first of these is beyond the Rhine and the lake ⁵ inclining towards the east, its ridge moderately elevated; here are the sources of the Danube near to the Suevi and the forest of Hercynia. ⁶ The other branches extend towards Illyria and the Adriatic, such are the Mount Apennine, already mentioned, Tullum and Phligadia, ⁷ the mountains lying above the Vindelici from whence proceed the Duras, ⁸ the Clanis, ⁹ and many other rivers which discharge themselves like torrents into the current of the Danube.