 Complete the following phrase:  The CIS has its origins with the Russian Empire, which was replaced in 1917 by the Russian Republic after the February Revolution earlier that year. Following the October Revolution, the Russian Soviet Federative Socialist Republic became the leading republic in the Soviet Union USSR upon its creation with the 1922 Treaty and Declaration of the Creation of the USSR along with Byelorussian SSR and Ukrainian SSR. When the USSR began to fall in 1991, the founding republics signed the Belavezha Accords on 8 December 1991, declaring that the 