Duk da haka, wasu bincike ya postulated cewa al'adu ci gaba sannu a hankali da kuma ci gaba, da kuma cewa gabatarwar Celtic harshe da kuma abubuwa na Celtic al'adu iya kasance a sakamakon al'adu musayar da Celtic kungiyoyin a kudu maso yammacin Turai daga Neolithic ga Bronze Age. The hasashe cewa 'yan qasar Late Bronze Age mazauna sannu a hankali tunawa Celtic tasirin tun da aka goyan bayan wasu 'yan kwanan nan kwayoyin bincike. Romawa da ake kira Ireland a matsayin Scotia 500 AZ da kuma daga baya Hibernia. Ptolemy, a 100 AZ, rubuce-rubucen da Ireland ta al'ummai. Ireland ya ba wani ɓangare na rinjayar da Celts daga nahiyar.
Tacitus