>>7062168You have to consider the factors that lead to civilization. Resources, exchange of knowledge between groups, even the culture of the group. Keep in mind most of Europe was ooga boogas before Romans took over and after the Romans fell Europe didn't really take off until the whole culture changed during the Rennaisance and even then the beginning days of the Rennaisance were largely fueled by previous Chinese and Middle Eastern science.
It's not hard to see how a secluded tribe could remain so primitive when you understand the factors that have caused development