After Rabbi Mordechai Yosef's death, his eldest son, Rabbi Yaakov Leiner, became Radziner Rebbe, until his sudden death on 5 Iyar 5769 (2009). Rav Yaakov studied at Yeshiva Rabbi Chaim Berlin, and then at Rabbi Nosson Dovid Rabinowitz's kollel in Shaarei Chesed. He received semichos from the Chief Rabbi of Jerusalem, Rabbi Yitzchok Kolitz and Rabbi Zalman Nechemia Goldberg. In the summer of 1996, he left the kollel to learn for six years in Beth Medrash Govoah in Lakewood, New Jersey, once again reuniting with a Radziner, the rosh yeshiva, Rabbi Yerucham Olshin. During those six years he reviewed his Yoreh Deah many times and went through many Talmudic tractates. In 1992, at the age of 30, he married Miriam, of the Bookson family of Monsey, New York. They had ten children. Rabbi Yaakov published all the writings of his grandfather, Rabbi Yeruchem, a few months before the former's death and considered that work to be his crowning achievement. After Rabbi Yaakov's death, his ideas were published in ""Tiferes Yaakov"".