1. The Significance of the 18th of Elul in Chabad History
The 18th day of Elul, known as Chai Elul—the “life” of Elul, is a day rich with significance in Chabad and Chassidic history. While most people associate this date primarily with the birthdays of both the Baal Shem Tov and the Alter Rebbe, there are actually several other important events that occurred on this day. The day marks not only personal milestones but also pivotal moments for the development and spread of Chassidus.2. The Passing of the Maharal of Prague
One notable event is the passing of the Maharal of Prague, Rabbi Yehuda Loewy, on Chai Elul in the year שס"ט (5369 — 1609). The Maharal was a towering Torah scholar, philosopher, and Kabbalist whose works addressed both revealed and mystical aspects of Torah. He is also significant to Chabad as a direct ancestor of the Alter Rebbe, seven generations back. The lineage runs from the Maharal through his son Rabbi Betzalel, then Rabbi Shmuel, Rabbi Yehuda Loewy, Rabbi Moshe, Rabbi Schneur Zalman (not to be confused with the Alter Rebbe), then Baruch, and finally to Rabbi Schneur Zalman of Liadi himself. This lineage traces back even further to King David through the Geonim, establishing a royal and spiritual heritage for all subsequent Lubavitcher Rebbes.3. The Miraculous Birth and Early Life of the Baal Shem Tov
The Baal Shem Tov was born on Chai Elul in the year תנ"ח (5458 — 1698), in a settlement called Okup. His father was Reb Eliezer and his mother Sarah, both righteous individuals who were blessed with him at an advanced age—his father was 100 and his mother 90 when they received a dream foretelling his birth. This parallels Avraham and Sarah’s story in Torah. From infancy, the Baal Shem Tov’s life was marked by miracles: he walked and talked at three months old, lost both parents by age two-and-a-half, yet displayed remarkable fearlessness and spiritual awareness. A recently discovered note written by the Alter Rebbe recounts these early years with unique details: At three years old, during a stormy night, he entered a forest unafraid except for Hashem—God Himself. There he encountered forces of evil who tried to frighten him into denying divine providence but he stood firm in faith. Up until age eighteen he was taught by Achia HaShiloni in mystical ways, later even meriting instruction from Mashiach himself.4. The Baal Shem Tov’s Spiritual Development and Revelation
There are varying accounts regarding when Achia HaShiloni began teaching the Baal Shem Tov—some say from age three until eighteen, others that it began when he turned twenty-six on Chai Elul in תפ"ד (5484 — 1724). In a letter to his student Reb Yaakov Yosef HaKohen, the Baal Shem Tov describes how Achia HaShiloni appeared to him at midnight on his twenty-sixth birthday to begin teaching him inner Torah secrets as studied in Gan Eden. The Baal Shem Tov’s public revelation also occurred on Chai Elul: at age thirty-six (תצ"ד, 5494 — 1734), after completing ten years of study with Achia HaShiloni and finishing all five books of Torah together, he was instructed to reveal himself as a miracle worker and teacher of Chassidus. For six years prior he had resisted this call but ultimately fulfilled his mission as directed by his teacher.5. The Birth and Early Years of the Alter Rebbe
Chai Elul is also celebrated as the birthday of Rabbi Schneur Zalman of Liadi—the Alter Rebbe—author of Tanya, Shulchan Aruch Harav, and founder of Chabad Chassidus. His parents, Reb Baruch and Rebbetzin Rivka, were childless for ten months after marriage until they sought a blessing from the Baal Shem Tov during his annual Chai Elul celebration meal (seudah). The Baal Shem Tov promised them that within exactly one year they would have a son dedicated to Torah study and service according to Chassidic teachings. On Wednesday (Yom Revi’i), Chai Elul in תק"ה (5505 — 1745), their son Schneur Zalman was born—a “new soul” destined to illuminate both revealed Torah and Chassidus with self-sacrifice until Moshiach’s arrival. On that day, after returning from immersion in the mikvah, the Baal Shem Tov displayed unusual joy during prayers—using festive tunes and omitting Tachanun, turning it into a festival-like occasion (a conduct of the Baal Shem Tov on account of the birth; regarding the standing Lubavitch custom, see below)—and explained that just as Wednesday saw creation’s luminaries placed in heaven so too did this day see a new luminary descend into our world.6. The Alter Rebbe’s Upsherin (First Haircut) by the Baal Shem Tov
Three years later on Chai Elul in תק"ח (5508 — 1748), marking his third birthday (upsherin), Reb Baruch brought young Schneur Zalman to Mezhibuzh for his first haircut performed personally by the Baal Shem Tov. The Baal Shem Tov instructed that immediately after cutting his hair—leaving side-locks (peyos)—they should return home without delay so that Schneur Zalman would not become attached to him but rather learn from his future teacher, the Maggid of Mezritch. During this visit, after performing the haircutting ceremony together with Rebbetzin Rivka and her sister-in-law Devorah Leah present, the Baal Shem Tov blessed them with Birkas Kohanim—the priestly blessing—and made a feast for all students where he taught about Avraham recognizing God at age three—a hint to Schneur Zalman’s own spiritual destiny.7. Settlement of Lubavitch as Chabad Headquarters
On Chai Elul in תקע"ג (5573 — 1813), the Mittler Rebbe Dov Ber settled permanently in Lubavitch following requests from Russian chassidim after several months living elsewhere post-Alter Rebbe’s passing. Upon arrival with thousands accompanying him, he chose an empty lot where homes had burned down two years prior—a site where as a child he had learned Torah—and established Lubavitch as headquarters for four generations: Mittler Rebbe, Tzemach Tzedek, Maharash, Rashab. Lubavitch became synonymous with deep spiritual striving—its forests providing seclusion for contemplation—and served as center for hundreds of thousands across Russia for over a century.8. Founding of Tomchei Temimim Yeshiva on Chai Elul
In more recent history, on Chai Elul in תרנ"ז (5657 — 1897)—three days after the yeshiva was founded on 15 Elul—the official study began at Yeshivas Tomchei Temimim Lubavitch, established by the Rebbe Rashab during the sheva brachos celebrations for his son (the previous Rebbe). On this day eighteen students were chosen as its first cohort, under the guidance of prominent chassidim. At its founding meal on Chai Elul—the joint birthday of both Baal Shem Tov and Alter Rebbe—the Rashab declared that this yeshiva would produce students wholly dedicated to Torah learning and service according to Chassidus’ path so that “the wellsprings will spread outward,” hastening Moshiach’s coming per promise given to Baal Shem Tov.9. Customs Regarding Saying Tachanon on Chai Elul
Although many Chassidic holidays are marked by omitting Tachanun, officially Chai Elul is not one such day according to standard Lubavitch custom—even though it commemorates such joyous events as these births and revelations. There has been some debate about whether or not it should be omitted; often if there is another reason such as presence of a groom (chatan) it is skipped anyway out of honor—but formally it remains an ordinary weekday regarding Tachanun. Nevertheless many communities treat it informally like a festival due to its profound significance within Chassidic tradition.