Across the centre of Europe the Celts move gradually west through Germany into France, northern Spain and Britain. This branch contains two sub-branches: Continental Celtic and Insular Celtic. By about 600 BCE, Celtic-speaking tribes had spread from what today are southern Germany, Austria, and Western Czech Republic in almost all directions, to France, Belgium, Spain, and the British Isles, then by 400 BCE, they also moved southward into northern Italy and southeast into the Balkans and even beyond. During the early 1st century BCE, Celtic-speaking tribes dominated a very significant portion of Europe. On 50 BCE, Julius Caesar conquered Gaul (ancient France) and Britain was also conquered about a century later by the emperor Claudius. As a