The title is taken from Judges 9:51: "a strong tower."
Rabbi Shem-Tov ben Abraham Ibn Ga'on
Early fourteenth century
Spain.
Rabbi Shem-Tov was the first scholars to systematically identify the sources for Maimonides' rulings in the Mishneh Torah. In addition to defending the Mishneh Torah from attacks by critics, especially the Ravad, the Migdal Oz cites from Maimonides' responsa, and corrects textual errors that crept into the manuscripts. It also mentions some changes that were introduced by Maimonides himself.