This chapter is a follow-up to my essay “Governor-Generalships in the Russian Empire: From an Ethnic to a Spatial Approach” in the collection Studies of New Imperial History and Nationalism in the Post-Soviet Space, published under the aegis of Ab Imperio in 2004.1 That essay argued that the Russian Empire was not a mere extension of the Muscovite State but was a union of three core regions: the original Muscovite territory, the Volga-Urals (the former Kazan Khanate), and the Left-Bank Ukraine (Cossack territory). This territorial union took shape from the second half of the sixteenth to the first half of the seventeenth century. Administratively and judicially, this core territory had become nearly homogeneous through the voevoda system. It was not by chance that the Petrine government replaced this system with a gubernatorial system, precisely when Russia was expanding beyond its territorial core. Despite the further rapid expansion of the empire, its core did not expand. Symptomatically, more than two centuries after the Pereiaslav Treaty of 1654 (which completed the formation of the imperial core by incorporating the Left-Bank Ukraine), only New Russia (Novorossiya, South Ukraine) was privileged to participate in the “core club,” which enjoyed the fruits of zemstvo and judicial reforms. At the same time, governor-generalships were specified as an institution for peripheral administration. Thus, the Great Reforms consolidated the bipolar structure of an empire with a core and peripheries.