The messiah, we know, can appear in a heartbeat. A messianic belief system, by contrast, is built up painstakingly over time. As the historian Menachem Friedman has shown, Lubavitch Hasidism has awaited the imminent arrival of the messiah since the early twentieth century, when the movement was led by the fifth Lubavitcher rebbe, Shalom Dovber Schneerson. Chabad’s messianic worldview, Friedman explains, developed as a response to the various pressures of modernity, in particular the haskala (Enlightenment), secularization, and Zionism.⁹ While traditional Judaism viewed these developments with concern, the fifth Lubavitcher rebbe saw them as foretelling the coming of the messiah. He declared the intellectuals of the haskala and the Zionists “enemies of God” and warned that as these representatives of the sitra ahra (in Aramaic, “the other side,” i.e., the forces of evil) grew more powerful, it fell to Chabad to save humanity from the encroaching iniquity.¹⁰ Only Chabad, he believed, could be the beacon of light in an ocean of darkness.

The idea that mankind stood at the threshold of the messianic age, and that Chabad was destined to play a major role therein, was later taken up by Shalom Dovber’s son, Rabbi Yosef Yitzchok Schneersohn, upon his succession as the sixth Lubavitcher rebbe in 1920. In the decades that followed, Yosef Yitzchok was to face a series of staggering challenges, both physical and theological: the Soviet regime’s brutal suppression of Judaism; the Nazi occupation of Europe; the Holocaust; and, finally, the establishment of the State of Israel by secular Zionists. Through most of the turbulent 1930s, Yosef Yitzchok himself had been forced to wander across Europe in search of safe haven until, at the urging of his followers, the Americans finally smuggled him into the United States.¹¹

By the time he arrived in America in the early 1940s, Yosef Yitzchok thought he knew why disaster had befallen the Jewish people: God had decided to bring an end to the exile and thus trigger mass tshuva (“repentance”) among the Jews in preparation for the messiah’s arrival. He believed that an event as catastrophic and incomprehensible as the Holocaust could only be followed by an equally astonishing and inconceivable salvation.¹² “We are living in the last days before the redemption,” he declared.¹³ All that remained was to “polish the buttons,” i.e., take care of minor details.¹⁴

The sixth rebbe passed away in 1950 after a long battle with multiple sclerosis. His successor, Menachem Mendel Schneerson, was forty-eight years old when he accepted the mantle of Chabad’s leadership. Blessed with both good yichus (“family lineage”) and, as was roundly acknowledged, a striking and charismatic personality, Menachem Mendel was born in the southern Ukraine to Rabbi Levi Yitzchak Schneerson, who was himself the great-grandson of the third Lubavitcher rebbe, known as the Tzemach Tzedek (“Righteous Sprout,” or “Righteous Scion”). In 1923, Menachem Mendel became a close student of the sixth rebbe, and in 1928, he married the rebbe’s daughter, Chaya Moussia, in Warsaw. The two moved to Berlin, and Menachem Mendel began to audit university classes in mathematics and philosophy. When the Nazis came to power in 1933, he escaped with his wife to Paris, where he completed a degree in electrical engineering at a technical college.¹⁵ After the German invasion of France, he fled again, this time to New York, where he assumed various Chabad leadership positions (as well as working a stint at the Brooklyn Navy Yard). Throughout this period, however, he maintained a relatively low profile, rarely making appearances or speaking in public.

Menachem Mendel’s appointment as the seventh Lubavitcher rebbe was by no means a foregone conclusion. His brother-in-law, Rabbi Shemaryahu Gurary, was married to the rebbe’s eldest daughter and was also considered a strong contender for the position. The scales eventually tilted in Menachem Mendel’s favor, however, and he formally assumed leadership of Chabad a year after his father-in-law’s death. According to Friedman, the decisive factor in Menachem Mendel’s ascent was his zealous commitment to Yosef Yitzchok’s messianic theology.¹⁶ Either way, it would soon become clear that the seventh rebbe’s messianic fervor surpassed that of all his predecessors—and had a deeply personal dimension.