The Kalimantan Physical Revolution () was an armed conflict between Indonesian nationalists in and pro-Dutch forces in Dutch Borneo following the end of the Japanese occupation of the Dutch East Indies and the 1945 Proclamation of Indonesian Independence by Sukarno and which lasted until the Dutch withdrew from most of Indonesia in 1949. It can be considered a regional conflict in the larger Indonesian National Revolution. After the surrender of the Japanese at the end of World War II, allied forces took control of the Dutch East Indies, including Dutch Borneo. The return of Dutch authorities however, was rejected by majority of native population, including in Borneo, resulting in various regional armed conflicts between Royal Netherlands East Indies Army and Indonesian nationalist forces. Allied military forces in Borneo were in a strong position after an early conflict in August 1945, and were able to pacify local nationalist uprisings and impose a blockade to prevent military aid and exchange in personnel from nationalist strongholds in Java and Sumatra. Later, nationalists with connections to Borneo were able to breach the military blockade to provide information of revolutionary events in Java and Sumatra, declaring Kalimantan as inseparable part of the new Indonesian republic (the so-called Kalimantan proclamation).