Peter the Great was the czar of Russia from 1682 to 1725, according to A&E's Biography, and he was responsible for reforming Russia, bringing it into the modern age and setting the stage for Russia to become a world power. Previously, Russia remained isolated from the West and missed out on many of the societal gains that resulted from the Renaissance, a problem Peter corrected during his rule.
In 1682, Peter and his brother Ivan IV became rulers of Russia, and when Ivan died in 1696, Peter became the sole sovereign. Early on, Peter realized that Russia had missed out on the technological advancements that swept through Europe, so he appointed scientists to educate the Russian people. He established the country's first modern ruling body, abolishing an older and much less efficient method of administrating Russia.
Peter built up Russia's naval power, making it a force to be reckoned with on the seas, and he oversaw several military campaigns that gained Russian territory in the West. One of his greatest tactical victories was against Sweden, when he drew their army north during a particularly brutal Russian winter. When Peter died in 1725, he left behind a country that was vastly different from the one he inherited.