The Visionary Rebbe: Rabbi Gershon Henoch Leiner of Radzin

A Brilliant Mind with a Revolutionary Spirit

One of the most fascinating figures in the world of Hasidism was Rabbi Gershon Henoch Leiner of Radzin, known as the Rebbe of Radzin. Born in 1839, he was a prodigy and towering scholar, deeply engaged in some of the most significant halachic (Jewish legal) controversies of his day.

To clarify these complex issues, Rabbi Leiner traveled extensively—even to remote countries—consulting scientists, acquiring broad academic knowledge, and famously carrying a pistol in his satchel for protection along the way. He combined rigorous Torah scholarship with an unyielding pursuit of truth, wherever it led.

The Etrog Controversy and Defense of Korfu

One of the first halachic debates that Rabbi Leiner immersed himself in was the dispute over the etrogim (citrons) from the Greek island of Korfu. For many years, growers in Korfu sold their etrogim at extraordinarily high prices, knowing how much Jews were willing to spend to fulfill this mitzvah.

Eventually, some rabbinic authorities called to ban Korfu etrogim and instead use only etrogim from the Land of Israel, both to support its inhabitants and due to concerns that the Korfu etrogim might be grafted and thus halachically invalid. Rabbi Leiner undertook an investigation of his own, traveled to examine the etrogim directly, and concluded that they were not grafted. He saw no reason to invalidate them. He even journeyed to Lithuania to present his findings and attempt to convince leading Torah authorities of his position.

Techelet, the Vatican, and a Burning Hope for Redemption

Rabbi Leiner yearned deeply for redemption. According to some accounts, he managed to enter the underground vaults of the Vatican in Rome and saw there the tzitz, the headplate worn by the Kohen Gadol (High Priest). He also made preparations to obtain a red heifer to purify the Jewish people from ritual impurity.

But his most famous project was the revival of techelet, the ancient blue dye once used in tzitzit. Today, many Jews wear a strand of techelet on their tallit, but in Rabbi Leiner’s time, techelet had long vanished from Jewish life and was considered part of a lost past.

Rabbi Leiner began his investigation through texts, learning Latin to access ancient sources that described techelet. He then traveled far and wide, meeting marine biologists and chemists, and ultimately produced a blue dye from a sea creature known as Janthina (translated in his writings as the “dyer’s cuttlefish”). His identification ignited passionate debate, but to this day, some Jews continue to wear the genre of techelet he discovered.

Writings, Criticism, and Enduring Impact

Rabbi Leiner also authored a monumental and innovative series of works on Seder Taharot (the laws of purity), driven by his desire to hasten redemption. These writings, too, sparked heated debate. Some scholars criticized them, while others praised their brilliance.

A man of many talents, he had knowledge of medicine and pharmacology and would write prescriptions for his followers.

Rabbi Gershon Henoch Leiner passed away in 1891, leaving behind a massive body of writings and revolutionary ideas that continue to shape halachic discussions to this day.