Rabbi Moshe ben Maimon (Rambam, Maimonides — see 2nd article,) and the great Moroccan Jewish Kabbalist, Rabbi Yaakov Abuhatzeira (see 1st article), both have yahrzeits this Sunday night - Monday., while the yahrzeit of Rabbi Shneur-Zalman, first in the Chabad dynasty (see 3rd article) falls on Erev Shabbat.