There were several reasons for Russia’s expansion. First of all, the landlocked nation needed access to the sea. Secondly, the ruling class of Russia was a land-rich aristocracy, which profits from territorial expansion. Sometimes, the expansion may have had ideological underpinnings, for example, the idea of third Rome, Pan-Slavism, or later, Communism.And finally, the empire may have continued to expand almost accidentally - by the need to bridge already conquered territories