By archaeological data, two stages or separate time periods in the development of the Narva culture can be distinquished in the prehistoric northern East Baltic. One stage is in the Early Neolithic, when the Early Narva culture was spread throughout the territory of present-day Estonia, Leningrad, Pskov and the western Smolensk area. It is possible that the Balto-finnougric hydronyms that linguists encounter in the territories of Estonia, Leningrad and Novgorod area from this time period.
During the second time period in the East Baltic, two distinct processes occurred. In the Middle Neolithic, north of the Daugava River and right up to Finland Bay, the Finno-Ugrians adopted many features of material and spiritual culture from the people of the Narva culture while they were spreading their own influence.We can consider this period the early pro-Baltic period, when the Finno-Ugrians adopted many elements of Narva material culture and enriched their lexican with the langua-ge of Narva material culture peoples. We can call this time period the Finno-Ugrinization period of the northern Narva culture
A different process occurred in the Middle and Late Neolithic south of the Daugava River. The Finno-Ugrians lived on separate islands within this Late Narva culture territory. Finno-Ugric hydronyms and traces of material culture have remained in this territory up to present times.