Peter I, also known as Peter the Great, was a Russian TSAR who reigned from 1682 to 1725. He is widely regarded as one of the most influential rulers in Russian history and is credited with transforming Russia into a major European power. His reign saw the introduction of sweeping reforms, including the modernization of the Russian military, the expansion of the Russian Empire, and the establishment of the Russian Orthodox Church. The term 'CZAR' is derived from the Latin word 'CAESAR' and is used to refer to an emperor or king, while the term 'TSAR' is derived from the Slavic word for 'CAESAR' and is used to refer to a Russian emperor.