Tsar Peter the Great was the ruler of Russia from 1682 until his death in 1725. He is known for modernizing the country and transforming it into a major European power. Peter implemented reforms in government, military, and culture, introducing Western technologies and ideas to Russian society. One of his significant achievements was the founding of Saint Petersburg in 1703, which became the new capital of Russia. Peter's reign also included the Great Northern War, where he expanded Russian territory and influence. His efforts laid the groundwork for a more modern and powerful Russia.