David Eliezrie's Undaunted chronicles the extraordinary courage of the Sixth Lubavitcher Rebbe, Rabbi Yosef Yitzchak Schneersohn, as he confronted the brutal oppression of both czarist Russia and the Soviet regime. While many religious leaders fled as the Communists shuttered synagogues and schools, Rabbi Schneersohn remained, risking his life to preserve Jewish life and earning the reputation of "the last man standing." Despite enduring torture, arrest, and a death sentence, his unwavering defiance and international advocacy ultimately secured his release. Drawing on historical documents and rare archives, Eliezrie details how Rabbi Schneersohn introduced Chabad teachings in Western Europe, empowered women, and established yeshivas to nurture future Jewish leaders. The book recounts his daring escape from war-torn Poland - a feat made possible through a rare collaboration between the US government and Nazi Germany - and his dramatic arrival in the United States. There, he boldly declared "America is not different," directly challenging the widespread belief that Judaism must conform to American culture. Even after his exile from the Soviet Union, Rabbi Schneersohn continued to lead Jewish resistance there and worked tirelessly to save Jews. He reenvisioned American Jewry by founding the first nationwide network of Jewish day schools, and in the postwar years, laid the groundwork for a global Jewish renaissance, inspiring generations of Chabad leaders to sustain and expand Jewish life in the face of adversity. Undaunted also explores the deep relationship between the Sixth Rebbe and his successor, Rabbi Menachem Mendel Schneerson. In an era of unparalleled turmoil and challenge, the Rebbe emerges as one of the most consequential leaders of modern Jewry.