According to the Rome agreements signed on May 18, 1941 by Benito Mussolini and the head of Independent State of Croatia (ISC) Ante Pavelić, Croatian side had to cede a large part of eastern Adriatic coast to Kingdom of Italy. Rome agreements also stipulated that ISC does not have right to develop navy at the parts of Adriatic coast that remained within the Croatian borders. After German attackon Soviet Union Croatian volunteers joined German and Italian troops fighting on the Eastern front. Croatian naval legion was also formed and it joined the German navy on the Black sea. After the capitulation of Italy in September 1943 Croatian authorities declared Rome agreements null and void and most of the areas annexed by Italians in 1941 were returned to Croatian rule. This opened the opportunity for the development of ISC Navy atthe Adriatic. Unlike Italians before them, Germans were ready to help ISC to establish its naval forces. But because of the difficult situation during the later part of the war ISC Navy at the Adriatic was very limited in its operations. In late 1944 some ISC naval personnel defected to the Tito’s partisans and after that Germans lost confidence in ISC Navy. From 1941 ISC Navyhad port authorities and various commands on Croatian rivers (Danube, Drava and Sava). Its main bases were in Brod na Savi and Zemun. ISC Navy at rivers possessed several patrol boats. During Axis attack on Kingdom of Yugoslavia in April 1941 most of its river boats were scuttled bytheir crews. During 1942 and 1943 some of these boats were salvaged, among them two monitors („Bosna“ and „Sava“), and taken into service of the ISC Navy. Because of the activities of partisan forces operating in Slavonia, Syrmia and Bosnia regular traffic along river Sava was disrupted from 1942 and ISC Navy was not able to control the situation at that river. During 1944 Allied airplanes began laying mines in Sava and one of it hit and sank monitor „Bosna“. In late summer of 1944 Soviet Red army was approaching Croatian border and Marshal Tito issued a call to soldiers of Croatian Home Guardsto join the partisans until September 15 or face consequences as „traitors“. Many Hom Guardsmen deserted their units and joined the partisans. ISC naval personnel in Brod na Savi scuttled monitor „Sava“ and also deserted to partisans. In October 1944 Soviet and partisan forces captured Belgrade and eastern Syrmia, including Zemun. Because of such developments of events ISC Navy at rivers largely ceased to exist already in autumn of 1944, although the war lasted for several more months.
