Rabbi Shem Tov ben Isaac Ganguine was born in Jerusalem to a scholarly Moroccan family that had been in the land of Israel since the Spanish Inquisition. He served as a rabbi, judge and rosh yeshiva, in Egypt and England, leading both Ashkenazi and Sephardic communities despite his own Sephardic heritage. A poet and prolific writer on topics including theology, Jewish law, Bible, and philology, many of his works remain in manuscript or have been lost. He is best known for his Keter Shem Tov, an encyclopedic treatise on variant customs among Sephardic and Ashkenazi communities.