The pilgrimage to Uman rests on a specific instruction its central figure gave his followers before he died, not on a general custom that grew up afterward.
A grave visit as religious obligation
Rebbe Nachman of Breslov, founder of Breslov Hasidism, died in Uman in 1810 at a young age and reportedly told his followers that gathering at his grave on Rosh Hashanah specifically was of great spiritual value, a directive his followers have treated ever since as close to a binding instruction rather than an optional custom, distinguishing the Uman pilgrimage from most other Hasidic grave-visiting traditions built up gradually by followers rather than commanded by the figure himself.
Banned, then revived
Soviet authorities suppressed the pilgrimage for most of the twentieth century, and travel to Uman for Hasidic visitors was effectively impossible for decades under Soviet rule. The pilgrimage resumed and grew rapidly after Ukraine's independence in 1991, expanding from a small trickle of visitors to tens of thousands annually by the early twenty-first century.
Continuing through war
Since Russia's full-scale invasion of Ukraine in 2022, pilgrims have continued travelling to Uman for Rosh Hashanah despite the conflict, sometimes against the advice of Israeli and Ukrainian authorities and amid direct security incidents near the city, treating the specific instruction attributed to Rebbe Nachman as outweighing the practical risks involved.