Shemaryahu Gurary
He was the older son-in-law of Rabbi Yosef Yitzchok Schneersohn ( 1880-1950 ) , known as "Rebbe Rayatz" , the sixth Rebbe of the Chabad-Lubavitch Hasidic movement , and the brother-in-law of Rabbi Menachem Mendel Schneerson ( 1902-1994 ) , the seventh Lubavitcher Rebbe . 
<triplet> Yosef Yitzchok Schneersohn <subj> Rebbe <obj> position held <subj> Menachem Mendel Schneerson <obj> relative <triplet> Menachem Mendel Schneerson <subj> Yosef Yitzchok Schneersohn <obj> relative <subj> Rebbe <obj> occupation