Russian imperialism under various regimes has often been denounced, and rarely praised. Even more seldom has it been defined. In fact, it is more difficult to define than to condemn. One difficulty lies in the fact that from the time, beginning in the 1450s, of the final unification of the principalities of central Russia around a single center of power—Moscow—the Muscovite state itself was constantly expanding through the settlement of Russian peasants across the Eastern European plain, while even in this earliest period various non-Russian peoples came under Muscovite rule. At what point does “expansion” end and “imperialism” begin?