Međimurje Secession Day is observed in Croatia on January 9, commemorating the region's secession from Hungary in 1919 and its subsequent integration into what would become Yugoslavia. This day marks the historical transition of Međimurje, which is the smallest and most densely populated county in Croatia, from Hungarian rule to joining the Kingdom of Serbs, Croats, and Slovenes. The region, located between the Drava and Mura rivers, has a rich history dating back to the Stone Age and has experienced various administrative changes, including its connection to the Habsburg Kingdoms of Hungary and Croatia. On this day, people in Croatia reflect on the significance of this event in their national history, recognizing the region's cultural heritage and its journey towards becoming part of modern Croatia.