Zaporizhian Sich
From the 16th to the 18th centuries the Zaporizhzhia region functioned as semi-independent quasi-republican Cossack territory centred on the Zaporizhian Sich. Sometimes the region is referred to as "Zaporizhian Sich" as well. Zaporizhzhia corresponds to modern Dnipropetrovsk Oblast, major parts of Zaporizhzhia and Kirovohrad Oblasts, as well as parts of Kherson and Donetsk Oblasts of Ukraine.