This culture was a maritime trading-networked culture that included Brittany and most of the rest of France, the other Celtic nations, England, Spain and Portugal. According to John T. Koch, Barry Cunliffe, Karl, and Wodtko, Celtic languages developed in the intense interactions of this culture with the Tartessian language the first written language so far discovered from this era, but this view stands in contrast to the more generally accepted view of Celticists that their origin lies with the Central European Hallstatt culture and that Tartessian cannot be classified as Celtic at all.