At the beginning of World War I, the town of Boyan was completely destroyed by invading armies. The Rebbe and his family escaped to Vienna, where the Rebbe died in 1917. After the war ended, three of his four sons each moved to a different country to establish their court. His eldest son, Rabbi Menachem Nachum (1869–1936), became the Boyaner Rebbe in Czernowitz, Bukovina. Rabbi Menachem Nachum's two sons, Rabbi Aharon and Rabbi Mordechai Shraga, succeeded him; they and their families were murdered by the Nazis during World War II. Rabbi Menachem Nachum's son-in-law, Rabbi Moshenu (1841–1943), became the Boyaner Rebbe in Kraków; he was murdered in Auschwitz.