In 983, during the reign of King Seongjong of Goryeo, a regional administrative unit called Najumok was established in Naju. This administrative system remained in place for an extraordinary 913 years, shaping the region's identity for nearly a millennium. It wasn't called by its current name from the start. In 995, when Goryeo divided the country into ten provinces, the area now known as Jeollabuk-do was called Gangnam-do, while the area now known as Jeollanam-do was called Haeyang-do — two entirely separate names.
That arrangement changed in 1018, the 9th year of King Hyeonjong's reign. That year, Goryeo restructured its ten-province system into a "five provinces, two frontier districts" system, merging Gangnam-do and Haeyang-do into a single unit. When it came time to name this newly merged region, the government drew on the first syllables of the two cities that were, at the time, the leading centers of the Honam region: Jeon from Jeonju (全州) and Ra from Naju (羅州). Combined, they formed "Jeollaju-do" — the origin of what would become "Jeolla-do." What's notable is that while the names and boundaries of Korea's other provinces shifted repeatedly over the centuries, Jeolla-do's name and rough territory remained almost unchanged throughout the entire Goryeo period, carrying through Joseon and continuing essentially intact to the present day. Etched into a regional name that has lasted over a thousand years is the enduring presence of the city of Naju itself.