The term Russian oligarch (see related term "New Russians") is used to describe wealthy businessmen of the former Soviet republics that rapidly accumulated their wealth during the era of Russian privatisiation in the aftermath of the dissolution of the Soviet Union in the 1990s. The failing Soviet state left the ownership of state assests contested, which allowed for informal deals with former USSR officials (mostly Russia and Ukraine) as a means to acquire state property. Analysts have drawn comparisons between the current Russian system of oligarchs and the system of powerful Boyars that emerged in late-Medieval Muscovy.