The Mishneh Torah was the Rambam's (Rabbi Moses ben Maimon) magnum opus, a work spanning hundreds of chapters and describing all of the laws mentioned in the Torah. To this day it is the only work that details all of Jewish observance, including those law
Chabad.org: Moshe Perlstein, Mendy Cohen, Moshe Weiss, Eli Nosson Silberberg, Chaim Schapiro, Eli Silberstein, Eliyahu Kaminetzky