Habad ḥasidism was founded by Shneur Zalman of Lyady (1745-1813) in the late 1700s. It has been led by his descendants ever since. The two Habad leaders represented in this collection are Joseph Isaac Schneersohn (1880-1950) who became the leader of Habad following the 1917 revolution in Russia, and his son-in-law Menaḥem Mendel Schneersohn (1902- ) who assumed the leadership of Lubavitch in 1950.
From the description of Poster collection, 1929-1973. (Yeshiva University). WorldCat record id: 122460497