The Zaporozhian Sich (, ; also , ; Free lands of the Zaporozhian Host the Lower) was a semi-autonomous polity and proto-state of Cossacks that existed between the 16th to 18th centuries, including as an autonomous stratocratic state within the Cossack Hetmanate for over a hundred years, centred around the region now home to the Kakhovka Reservoir and spanning the lower Dnieper river in Ukraine. In different periods the area came under the sovereignty of the Polish–Lithuanian Commonwealth, the Ottoman Empire, the Tsardom of Russia, and the Russian Empire. In 1775, shortly after Russia annexed the territories ceded to it by the Ottoman Empire under the Treaty of Küçük Kaynarca (1774), Catherine the Great disbanded the Sich. She incorporated its territory into the Russian province of Novorossiya. The term Zaporozhian Sich can also refer metonymically and informally to the whole military-administrative organisation of the Zaporozhian Cossack host. Name The name "Zaporizhia" refers to the military and political organization of the Cossacks and to the location of their autonomous territory 'beyond the Rapids' () of the Dnieper River. The Dnieper Rapids were a major portage on the north-south Dnieper trade route. The term sich is a noun related to the Eastern Slavic verb sich''' (сѣчь), meaning "to chop" or "cut"; it may have been associated with the usual wood sharp-spiked stockades around Cossack settlements. Zaporizhia was located in the region around Kakhovka Reservoir in today's south-eastern Ukraine (much of its territory is now flooded by the reservoir). The area was also known under the historical term, Wild Fields. History A possible precursor of the Zaporozhian Sich was a fortification (sich) built on the Tomakivka island () in the middle of the Dnieper River in the present-day Zaporizhzhia region of Ukraine. However, there is no direct evidence about the exact time of the existence of Tomakivska Sich, whereas indirect data suggest that at the time of Tomakivska Sich there was no Zaporozhian Sich yet. The history of Zaporozhian Sich spans six time-periods: the emergence of the Sich (construction of ) (1471–1583) as part of the Lesser Poland Province of the Polish Crown by inclusion in the Kiev Voivodeship (1583–1657) the struggle against the Rzeczpospolita (the Polish-Lithuanian state), the Ottoman Empire, and the Crimea Khanate for the independence of the Ukrainian part of the Rzeczpospolita (Commonwealth) (1657–1686) the struggle with Crimea, the Ottoman Empire, and the Russian Empire for the unique identity of