 About 1000 basic words of the Hungarian language – including the names of the seasons and natural phenomena, and the most frequently used verbs – had cognates in other Finno-Ugric languages, suggesting the temporary existence of a Proto-Finno-Ugric language. Between around 2600 and 2100 BC, climatic changes caused the spread of swamps on both sides of the Urals, forcing groups of inhabitants to leave their homelands. The Finno-Ugric linguistic unity disappeared and new languages emerged around 2000 BC. Whether the groups speaking the language from which Hungarian emerged lived to the east or to the west of the Urals in this period is debated by historians.
