The Zaporizhian Sich was a semi-autonomous polity of Cossacks that existed in Ukraine from 1552 to 1775. The polity was named for sichi, the fortified camps built by the Cossacks (a Ukrainian self-defense force created to defend against Tatar raids) to defend themselves from the Tatars of the Crimean Khanate. The Sich grew rapidly from serfs fleeing Poland-Lithuania, and it had a parliamentary system of government. The host went through a series of conflicts and alliances with the Tsardom of Russia, Poland, and Crimea, and the Sich joined the Cossack Hetmanate in 1649 during the Khmelnytsky Uprising. In 1654, the Sich became a protectorate of Russia, and, from 1734 to 1775, it stood off with the Russian Empire over the Russians' decision to cancel the Sich's autonomy. In 1775, following the Russian victory against the Ottoman Empire, Queen Catherine the Great disbanded the Sich and incorporated it into Novorossiya Governorate.