Peter the Great was most known for being the first to westernize Russia.
The Russian tsar most known for being the first to westernize Russia was Peter the Great. To find the answer to this question, you can use various resources such as history books, encyclopedias, or reliable websites that cover Russian history. You can search for information on each of the tsars mentioned and look for details about their policies and actions towards westernizing Russia. Comparing their contributions and impact on modernizing Russia will help you determine that Peter the Great was the one who played a significant role in westernizing the country.
