The Battle of Hill (Height) 731 (Greek: Μάχη του υψώματος 731), was a fierce battle fought during World War II in southern Albania, part of the Greco-Italian War. It began in the early morning of 9 March 1941, when Fascist Italy launched an assault (Operation Primavera) against Greece, aimed at capturing the critical mountain pass leading into the Kalpaki valley. Hill 731, strategically located 20 km north of Klisura (Këlcyrë) at the feet of Mount Trebeshinë, stood at the heart of the Greek defensive line.