The Day of the Polish Underground State is observed in Poland every September 27. This commemorative day celebrates the establishment of Poland's first underground organization during World War II, specifically the Service for Poland's Victory, created by General Juliusz Rómmel on September 27, 1939. The Polish Underground State refers to various resistance organizations loyal to the Polish government-in-exile, which included not only military efforts but also civilian initiatives such as social services and educational institutions. The day was officially introduced in 1998 and is marked by a solemn ceremony at the Monument to the Polish Underground State and Home Army in Warsaw, located in front of the Polish parliament. This remembrance day recognizes the significant involvement of hundreds of thousands of people in the underground resistance throughout the war.