The Gallo-Brittonic languages, also known as the P-Celtic languages, are a controversial subdivision of the Celtic languages of Ancient Gaul (both celtica and belgica) and  Celtic Britain, which share certain features. Besides common linguistic innovations, speakers of these languages shared cultural features and history. The cultural aspects are commonality of art styles and worship of similar gods. Coinage just prior to the British Roman period was also similar. In Julius Caesar's time, the Atrebates held land on both sides of the English Channel.