Albis: river in Germania, modern Elbe.
The ancient authors were aware that the river had its source in Bohemia, but were unsure about the exact location. Writing at the beginning of the second century, Tacitus tells that the river "rises in the territories of the Hermondurians";note[Tacitus, Germania 41.2.] the geographer Ptolemy thinks about the Sudeten Mountains;note[Ptolemy, Geography 2.11.1.]; and Cassius Dio, benefiting from the exploration during the Marcomannian campaigns of Marcus Aurelius, states that the source was in the Vandalician Mountains, or the Krkonoše, which is correct.note[Cassius Dio, Roman History 55.1.3)]The first Roman commander to reach the Elbe, was prince Drusus in 9 BCE,note[Cassius Dio, Roman History 55.1.2-4] and the first Roman to cross it was Lucius Domitius Ahenobarbus.note[Cassius Dio, Roman History 55.10a.2] Although it is often said that the Germanic Wars that started in 12 BCE were aimed at moving the imperial frontier from the Rhine to the Elbe, this is not mentioned in our sources. It is true that in 5 CE, Tiberius marched along the river for a considerable distance,note[Velleius Paterculus, Roman History 2.106.] but there is no proof that this was more than an exploration.
Among the tribes living along the river where the Langobards (along the Lower Elbe) and the Hermondurians (along the Middle Elbe), who both belonged to the Jastorf culture. In other words, they were German tribes. This is also true of the Semnones, who lived on the east bank, along the Havel and Spree. Along the Upper Elbe, the Celtic Boii gave their name to Bohemen; they were later replaced by the Germanic Marcomanni.