Tishrei 13 is the yahrtzeit of the fourth Rebbe of Chabad-Lubavitch, Rabbi Shmuel Schneersohn, known as “Maharash” (a Hebrew acronym for “our master Rabbi Shmuel”).
Rabbi Shmuel was born in the town of Lubavitch on the 2nd of Iyar of the year 5594 from creation (1834). His father was the third Chabad Rebbe, Rabbi Menachem Mendel [ http://www.chabad.org/search/keyword.asp?kid=2226 ] of Lubavitch (1789-1866).
Though the youngest of Rabbi Menachem Mendel’s seven sons, Rabbi Shmuel was chosen to succeed his father as the leader of Chabad Chassidism in the movement’s capitol, Lubavitch, at the latter’s passing in 1866 (four of his brothers established branches of Chabad in other towns in White Russia and Ukraine).
In addition to authoring and delivering more than 1,000 maamarim (discourses) of Chassidic teaching, Rabbi Shmuel was extensively involved in Jewish communal affairs and traveled throughout Europe in order to generate pressure on the Czarist regime to halt its instigation of pogroms against the Jews of Russia. Rabbi Shmuel passed away at the age of 48 on Tishrei 13, 5643 (1882).
More on the Rebbe Maharash: http://www.chabad.org/search/keyword.asp?kid=1580