R. Joseph Isaac Schneersohn (1880-1950), sixth rebbe in the Habad dynasty, was appointed Rebbe in 1917 and, after his expulsion in 1927, emigrated to the United States where his wisdom and erudite mind made the Lubavitcher movement the high profile hasidim, which they still retain.

R. Menahem Mendel Schneerson (1902–1994), was the seventh generation, in direct male descent of R. Shneur Zalman of Lyady, the founder of the movement and the dynasty. His main teacher in Jewish studies was his father R. Levi Isaac Schneersohn, who was rabbi of Yekaterinoslav (now Dnepropetrovsk) in south Russia, while his mother Hannah, the daughter of R. Meir Shlomo Yanovsky, rabbi of Nikolaev, took care of his general education which included Russian, French and mathematics. In 1924 he became engaged to his relative Hayyah Musiah.

Following the intervention of various governments, his future father-in-law was permitted to leave Soviet Russia in 1926, together with all the immediate members of his family, but R. Menahem Mendel was refused permission. As a result of strenuous efforts by his future father-in-law, however, he was enabled to come to Warsaw in 1929 where the marriage took place. It was already hinted at the wedding that R. Joseph Isaac, who had no sons, had designated Menahem Mendel as his successor, and after the marriage he began to instruct him for his future role, especially in the manuscripts of the previous Habad leaders, only a few of which had been revealed to the followers of the movement.