Rabbi Moshe Alshich, the Alshich HaKadosh, was born around 1507 in Adrianople (Edirne), Turkey, the son of Rabbi Chaim. He studied there in the yeshiva of Rabbi Yosef Karo and later in Salonica under Rabbi Yosef Taitatzak. In 1535 he went up to the Land of Israel and settled in Safed, where he soon stood out as a halachic authority: when Rabbi Yosef Karo arrived in Safed the next year, he was already serving there as a dayan. After Rabbi Yaakov Beirav renewed semicha, he was ordained by Rabbi Yosef Karo, and himself ordained Rabbi Yom Tov Tzahalon.

He headed two yeshivot in Safed and was one of the city's great preachers. Every Shabbat he preached before a large audience; his sermons were collected in his Torah commentary, Torat Moshe, and in commentaries on most books of the Bible. These works, rich in moral teaching, remain very popular. A hundred and forty of his responsa were published as She'elot uTeshuvot HaRav Moshe.

He was Rabbi Chaim Vital's teacher in Talmud and halacha; according to one tradition, the Arizal declined to teach him Kabbalah himself, and he received it only through Rabbi Chaim Vital. In old age, around 1590, he travelled as an emissary of Safed. He passed away on a 13 Nisan, around 1593 according to some sources and in 1600 according to others, and rests in the old cemetery of Safed, in the cave of Rabbi Yaakov Beirav.