Catherine II the Great (1729-1796), ruled the Russian Empire for 34 years from 1762 to 1796. She is the longest-reigning female leader in the history of Russia. She expanded her empire through conquest and diplomacy, making her one of the leading powers in Europe. By the end of her reign, about 200,000 square miles had been added to the territory of the Russian Empire. Catherine II was an able leader and carried out a number of educational and administrative reforms that had a lasting impact on her country. She founded the first women's educational institution in Russia, and the famous Hermitage became her personal collection. Catherine II also played a key role in encouraging the Russian Enlightenment, which saw the flourishing of the arts and sciences. She is considered one of the greatest monarchs of Russia, and such was her influence that the period of her reign is known as the Catherine Era.