The Koren Mesorat HaRav Siddur is the first complete, Orthodox prayer book with commentary by the seminal scholar and leader, The Rav, Rabbi Joseph B. Soloveitchik. The Siddur presents Rabbi Soloveitchiks exceptional insights on prayer, which have been adapted from his writings, public lectures, and classes. It is complemented by an elegant presentation in the renowned tradition of Koren Publishers Jerusalem, and an eloquent English translation and introduction by the esteemed Rabbi Sir Jonathan Sacks. Published in cooperation with the Orthodox Union. Rabbi Joseph B. Soloveitchik (1903-1993) was one of the twentieth centurys leading and most influential Talmudic scholars, Jewish philosophers, and religious leaders. A descendant of the Lithuanian Soloveitchik rabbinic dynasty, The Rav, as he was widely known, served as Rosh Yeshiva of the Rabbi Isaac Elchanan Theological Seminary at Yeshiva University, where he ordained nearly 2,000 rabbis over the course of almost half a century. Rabbi Soloveitchik advocated excellence in both Torah learning and Western, secular scholarship, as well as involvement in the broader community.