At the time that peter the great took the throne, the most essential part of the russian economy was

That would be the serfs.

Peter the Great or Peter Alexeyevich ascended to the throne in 1682. During that time the Russian economy was heavily reliant on serfs that is the unfree peasants, who were similar to medieval peasants. They worked on the land granted to them by nobility and they could not by law own land.

Acase involving the laws of a single state.