Royal Yugoslav Navy The Royal Yugoslav Navy ( Serbo - Croatian : Кpaљeвcкa Југословенска Pатна Морнарица ; " Kraljevska Jugoslovenska Ratna Mornarica " ) , was the navy of the Kingdom of Yugoslavia . This navy existed since the establishment of the Kingdom of Serbs , Croats and Slovenes in 1918 , which was changed in 1929 to the Kingdom of Yugoslavia . It was disbanded after the Axis invasion in April 1941 . History . Origins . Yugoslavia rose from the ashes of the Austro - Hungarian Empire , destroyed by the First World War . The new state , officially the Kingdom of the Serbs , Croats and Slovenes , was proclaimed on 1 December 1918 , prior to which date there had been a degree of chaos in the region , following the Armistice , when numerous " sailor ' s councils " and splinter factions had taken over many of the former Austro - Hungarian warships . Yugoslavia made demands for a large proportion of the former Empire ' s fleet . However , the Italians were extremely uneasy about the rise of a new naval power in the Adriatic area and pressed the Allies to distribute the Austro - Hungarian fleet among the victors . This was done , and only scraps of the former navy were allocated to Yugoslavia . The ships received were 12 modern torpedo - boat s , four obsolete minesweepers , four armoured river monitors and a number of auxiliaries . The fleet was further strengthened during the 1920s , when six minesweepers of the German " M " class and the old cruiser SMS " Niobe " were bought . Before the April 1941 invasion . On the eve of the Axis invasion of Yugoslavia , the Royal Yugoslav Navy was equipped with one elderly ex - German light cruiser ( suitable only for training purposes ) , one large modern destroyer flotilla leader of British design , three modern destroyers of French design ( two built in Yugoslavia plus another still under construction ) , one seaplane tender , four modern submarines ( two older French - built and two British - built ) and 10 modern motor torpedo boat s ( MTBs ) . Of the older vessels , there were six ex - Austrian Navy medium torpedo boats , six ex - German Navy minesweepers , five small minelayers , four large armoured river monitors and various auxiliary craft . Naval Operations during the Invasion of Yugoslavia . When Germany and Italy attacked Yugoslavia on 6 April 1941 , The Royal Yugoslavian Navy had available three destroyers , two submarines and 10 MTBs as the most effective units of the fleet . One other destroyer , the " Ljubljana " , was in dry - dock at the time of the invasion and she and her anti - aircraft guns were used in defence of the fleet base at Kotor . The remainder of the fleet was useful only for coastal defence and local escort and patrol work . Kotor was close to the Albanian border and the Italo - Greek front there , but Zara ( Zadar ) , an Italian enclave , was to the north - west of the coast and to prevent a bridgehead being established , the destroyer " Beograd " , four of the old torpedo boats and six MTBs were despatched to Šibenik , 80 km to the south of Zara , in preparation for an attack . The attack was to be coordinated with the 12th " Jadranska " Infantry Division and two " Odred " ( combined regiments ) of the Royal Yugoslav Army attacking from the Benkovac area , supported by air attacks by the 81st Bomber Group of the Royal Yugoslav Air Force . The Yugoslav forces launched their attack on 9 April , but by 13 April the Italian forces had counter - attacked and were in Benkovac by 14 April . The naval prong to this attack faltered when the destroyer " Beograd " was damaged by near misses from Italian aircraft off Šibenik when her starboard engine was put out of action , after which she limped to Kotor , escorted by the remainder of the force , for repairs . The maritime patrol float - planes of the Royal Yugoslav Air Force flew reconnaissance and attack missions during the campaign , as well as providing air cover for mine - laying operations off Zara ( Zadar ) . Some of their successes included an Italian tanker being damaged by a near miss off the Italian coast near Bari , attacks on the Albanian port of Durrës , as well as strikes against Italian re - supply convoys to Albania . On 9 April , one Dornier Do 22 K floatplane notably took on an Italian convoy of 12 steamers with an escort of eight destroyers crossing the Adriatic during the day , attacking single - handed in the face of intense AA fire . The Royal Yugoslav Navy also had at its disposal four large , heavily armed and armoured river monitor s in its riverine flotilla . They were used to patrol the Danube , Drava and Sava rivers in the northern parts of Yugoslavia and its border with Hungary . These monitors , the , , and had been inherited from the Austro - Hungarian Navy at the end of the First World War . All were of around 400 - 500t with a main armament of two 120mm guns , two or three 66mm guns , 120mm mortars , 40mm AA guns and machine guns . At the start of the campaign they had carried out offensive operations by shelling the airfield at Mohács in Hungary on the 6th of April and again two days later , but had to begin withdrawing towards Novi Sad by the 11th of April after coming under repeated attack by German dive - bombers . Early in the morning of 12 April , a squadron of German Junkers Ju 87 dive - bombers attacked the Yugoslav monitors on the Danube . The " Drava " was hit by several of them but they were unable to penetrate the " Drava " ' s 300mm thick deck armour , until , by chance , one put a bomb straight down the funnel , killing 54 of the 67 man crew . During the attack anti - aircraft gunners on the monitors claimed three dive - bombers shot down . The remaining three monitors were scuttled by their crews later on 12 April as German and Hungarian forces had occupied the bases and the river systems upon which they operated . Losses . The Italians captured most of the Yugoslav Navy ( one of its four destroyers , the " Ljubljana " , had spent the campaign in dry - dock ) . However , another destroyer , the " Zagreb " , was blown up at Kotor by its officers Mašera and Spasić to prevent capture and one of the British - built submarines and two MTBs succeeded in escaping to Alexandria in Egypt to continue to serve with the Allied cause . It should also be noted that a fourth destroyer was captured while under construction in the Cattaro shipyard , the " Split " , but the Regia Marina was not able to finish her before the armistice in 1943 . Eventually , she was recovered after the war by the Yugoslavians and completed under the original name . Ten Yugoslav Navy maritime patrol float - planes escaped to Greece , with nine making it to Egypt , where they formed a squadron under RAF command . A number of the surviving Yugoslav warships , notably the destroyers " Dubrovnik " , " Beograd " and the repaired " Ljubljana " , were used by the Regia Marina until the Italian Armistice of September 1943 , whereupon the Kriegsmarine and , to a lesser extent , the Navy of the Independent State of Croatia Croatian Forces appropriated the survivors for their own fleets . The destroyer " Ljubljana " was wrecked on a shoal near the Gulf of Tunis whilst in Italian service in April 1943 , but the " Dubrovnik " and " Beograd " were not sunk by Allied forces until April and May 1945 respectively . The light cruiser " Dalmacija " entered German service with the old name " Niobe " . Beached on Silba it was destroyed by British MTB 276 and MTB 298 in December 1943 . Several ships which survived the war continued their service with the Navy of Democratic Federal Yugoslavia .