 Complete the following phrase:  Catherine II the Great, who ruled in 176296, presided over the Age of Russian Enlightenment. She extended Russian political control over the Polish-Lithuanian Commonwealth and incorporated most of its territories into Russia during the Partitions of Poland, pushing the Russian frontier westward into Central Europe, and thus making Russia the most populous country in Europe. In the south, after the successful Russo-Turkish Wars against the Ottoman Empire, Catherine advanced Russias boundary to the Black Sea, defeating the Crimean Khanate. As a result of victories over Qajar Iran through the Russo-Persian Wars, by the first half of the 19th century, Russia also made significant territorial gains in Transcaucasia and the North Caucasus. Catherines successor, her son Paul, was unstable and focused predomitly on domestic issues. Following his short reign, Catherines strategy was continued with Alexander Is 180125 