The short-lived Act Zluky (Unification Act) was an agreement signed on 22 January 1919 by the Ukrainian People's Republic and the West Ukrainian People's Republic on the St. Sophia Square in Kyiv. This led to civil war, and an anarchist movement called the Black Army (later renamed to the Revolutionary Insurrectionary Army of Ukraine) developed in Southern Ukraine under the command of the anarchist Nestor Makhno during the Russian Civil War. They protected the operation of "free soviets" and libertarian communes in the Free Territory, an attempt to form a stateless anarchist society from 1918 to 1921 during the Ukrainian Revolution, fighting both the tsarist White Army under Denikin and later the Red Army under Trotsky, before being defeated by the latter in August 1921.