The name "Zaporizhia" refers to the military and political organization of the Cossacks and to the location of their autonomous territory 'beyond the Rapids' (za porohamy) of the Dnieper River. The term "sich" is a noun related to the Eastern Slavic verb sech′ (сѣчь) – "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 central Ukraine (much of its territory is now flooded by the reservoir). The area was also known under the historical term, Wild Fields.
A possible precursor of the Zaporozhian Sich was a fortification (sich) built on the Tomakivka island (Tomakivska Sich) in the middle of the Dnieper River in the present-day Zaporizhia 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 Zaporozhian Sich emerged as a method of defence by Slavic colonists against the frequent and devastating raids of Crimean Tatars, who captured and enslaved hundreds of thousands of Ukrainians, Belorusians and Poles in operations called "the harvesting of the steppe". The Ukrainians created a self-defence force, the Cossacks, fierce enough to stop the Tatar hordes, and built fortified camps (sichi) that were later united to form a central fortress, the Zaporozhian Sich.
Prince Dmytro Vyshnevetsky established the first Zaporizhian Sich on the island of Small (Mala) Khortytsia in 1552, building a fortress at Niz Dnieprovsky (Lower Dnieper) and placing a Cossack garrison there; Tatar forces destroyed the fortress in 1558. The Tomakivka Sich was built on a now-inundated island to the south, near the modern city of Marhanets; Tatars also razed that sich, in 1593. A third sich soon followed, on Bazavluk island, which survived until 1638, when it was destroyed by a Polish expeditionary force suppressing a Cossack uprising.