The Rhine was not known to Herodotus and first enters the historical period in the 1st century BC in Roman-era geography. At that time, it formed the boundary between Gaul and Germania. The Upper Rhine had been part of the areal of the late Hallstatt culture since the 6th century BC, and by the 1st century BC, the areal of the La Tène culture covered almost its entire length, forming a contact zone with the Jastorf culture, i.e. the locus of early Celtic-Germanic cultural contact. In Roman geography, the Rhine formed the boundary between Gallia and Germania by definition; e.g. Maurus Servius Honoratus, Commentary on the Aeneid of Vergil (8.727) (Rhenus) fluvius Galliae, qui Germanos a Gallia dividit "(The Rhine is a) river of Gaul, which divides the Germanic people from Gaul."