Theodor Mommsen ("The Provinces of the Roman Empire from Caesar to Diocletian", 1885) believed that the Germanic tribes of the region consisted of two parts, one having come under Roman influence and the other having remained outside of Roman influence, and he concluded that the Frisiavones were the same people as the Frisii. However, his reasoning parsed the accounts of Tacitus and Pliny selectively: he interpreted the 'Lesser Frisii' and 'Greater Frisii' of Tacitus to refer to the Roman-influenced Frisavones and the non-Roman-influenced Frisii; he considered Pliny's account that mentioned both the Frisiavones and the Frisii to be consistent with the model; and he rejected Pliny's account placing the Frisiavones in northern Gaul, saying that it "is beyond doubt incorrect".