The Primary Chronicle uses the name Dregovichs for an ancient Slavic tribe settled between Pripayt and Dvina rivers. The name comes from the Slavic word dregva (dryhva), "swamp". This tribe is thought to be ancestors of modern Poliszuks.
Their dialect, being close to Polish, Belarussian and Ukrainian languages, was recently assigned as dialect of Ukrainian.
Nowadays most of this populace remained self-concious is in Belarus. There were around 800 000 of them in 1931. The population of Polish and Ukrainian parts of Polesie assimilated with the respective nations.