Rabbi Mordechai ben Hillel HaKohen (c. 1250–1298), also known as The Mordechai, was a 13th-century German rabbi and posek. His chief legal commentary on the Talmud, referred to as The Mordechai, is one of the sources of the Shulchan Aruch. He was killed in the Rintfleisch massacres in 1298.
He was one of the first students of the Baal Shem Tov and the granfather of the famous Rabbi Meir of Premishlan II.
Rabbi Yaakov Yisrael Kanievsky, known as The Steipler or The Steipler Gaon, was a rabbi, Talmudic scholar, and posek.
Kabbalist and famous exorcist.