The conquest of Gaul marked the beginning of almost five centuries of Roman rule, which would have profound cultural and historical impacts. Roman rule brought with it Latin, the language of the Romans. This would evolve into Old French, giving the modern French language its Latin roots. Conquering Gaul enabled further expansion of the Empire into Northwestern Europe. Augustus would push into Germania and reach the Elbe, though settled on the Rhine as the imperial border following the disastrous Battle of the Teutoburg Forest. In addition to facilitating the conquest of parts of Germania, the Roman conquest of Britain led in 43 AD by Claudius also built on Caesar's invasions. The Roman hegemony would last, with only one interruption, until the Crossing of the Rhine in 406 AD.