Beginnings of Chassidut
Founded by the Baal Shem Tov, hassidic thought grew in Europe, branching off into many sects. One of the goals of hassidism is to reenergize Judaism and make Judaism accessible to the masses. Vehement opposition to this movement was led by the Vilna Gaon, and those people were refered to as "mitnagdim."
By Unknown author - This image is a colorized version of a 19th century B&W drawing by an unknown artist., Public Domain, https://commons.wikimedia.org/w/index.php?curid=18764913