Many features of the federal structure within the Russian Federation originate in the Union of Soviet Socialist Republics (USSR). In principle, the Soviet system was highly centralized from its creation in 1922, with the Moscow-centred ruling party, the Kommunisticheskaya Partiya Sovetskogo Soyuza, retaining practical and symbolic supremacy across the land. Following the disintegration of the USSR in 1991, the President of the Russian Federation, Boris Yeltsin, held a significant public profile, and was personally linked to the rapid political and economic transformations that enveloped Russia in the 1990s. With the onset of the Russian-supported separatist insurgency in the Donbas region of eastern Ukraine that followed the annexation of Crimea, the federal centre expanded its definition of what constituted a ‘security matter’ and was thus not subject to standard political procedures.