Yugoslav monitor Morava

The Yugoslav monitor Morava was a river monitor built for the Austro-Hungarian Navy as SMS Körös. During World War I she was part of the Danube Flotilla, and fought the Serbian and the Romanian Army. After World War I she was provided to the newly created Kingdom of Serbs, Croats and Slovenes (later Yugoslavia), and renamed Morava. During the German-led Axis invasion of Yugoslavia in April 1941, she was scuttled by her crew. She was subsequently raised by the navy of the Axis puppet state the Independent State of Croatia and continued in service as Bosna until June 1944 when she struck a mine and sank.

Description and construction
The ship was built for the Austro-Hungarian Navy by H. Schönichen and was named SMS Körös. She was laid down at Budapest in 1890 and had an overall length of 54 m, a beam of 9 m, and a normal draught of 1.2 m. Her displacement was 380 –, and her crew consisted of 79–84 officers and enlisted men. The ship was powered using steam generated by Yarrow water-tube boilers, and carried 54 LT of coal. The propulsion system was rated at 1200 shp and she was designed to reach a top speed of 9 kn.

Körös was armed with one double gun turret of 120 mm/L35 guns, two 66 mm/L42 guns, and two machine guns. Her armour consisted of belt and bulkheads 51 mm thick, deck armour 19 mm thick, and her conning tower had  51 mm thick armour, and her gun turret armour was 76 mm thick. Körös was completed and launched in 1892. Her sister ship, SMS Szamos was completed in 1893.

Serbian Campaign
Körös was commissioned into the Danube Flotilla, and at the start of World War I she was based at Zemun, just upstream from Belgrade on the Danube, with another three monitors and three patrol boats. Austria-Hungary declared war on the Kingdom of Serbia on 28 July 1914, and that night the Flotilla fired the first shots of the war against fortifications at the Zemun-Belgrade railway bridge over the Sava, although Körös was not initially involved. After a brief evacuation of the base at Zemun in September due to a Serbian counterattack, Körös, along with the monitor SMS Temes, a patrol boat and a minesweeper, broke through the minefields on the Sava near Belgrade and pushed upstream to join the fighting near Šabac. The Flotilla continued in action against Serbian forces at Belgrade until December, when her base was withdrawn to Petrovaradin for the winter. This continued until October 1915 when the Serbs evacuated Belgrade in the face of an Austro-Hungarian assault. During the final river crossing and support of the resulting bridgehead, Körös provided close support, during which her stack was hit and damaged. Following the capture of Belgrade, the Flotilla sailed downstream to Orșova near the Hungarian-Romanian border and waited for the lower Danube to be swept for mines. They then escorted a series of munitions convoys down the Danube to Lom where they were transferred to the Bulgarian railway system for shipment to their ally Turkey.

Romanian campaign
In November 1915, Körös and the other monitors were assembled at Rustschuk, Bulgaria. The position of Romania was uncertain, with the Central Powers being aware that the Romanians were negotiating to enter the war on the side of the Entente. To protect the 480 km long Danubian border between Romania and Bulgaria, the Flotilla established a sheltered base in the Belene Canal. When the Romanians entered the war on 27 August 1916, the monitors were again at Rustschuk, and were immediately attacked by three improvised torpedo boats operating out of the Romanian river port of Giurgiu. The torpedoes that were fired missed the monitors but struck a lighter loaded with fuel. The Second Monitor Division, consisting of Körös and three other monitors, was tasked with shelling Giurgiu, and subsequently set fire to oil storage tanks, the railway station and magazines, and sank several Romanian lighters. While the attack was underway, the First Monitor Division escorted supply ships back to the Belene anchorage. The Körös and her companions then destroyed two Romanian patrol boats and an improvised minelayer on their way back to Belene. This was followed by forays of the monitors both east and west of Belene, during which both Turnu Măgurele and Zimnicea were shelled.

In April 1918, Körös, along with three other monitors, two patrol boats and a tug were formed into Flottenabteilung Wulff under the command of Flottenkapitän (Fleet Captain) Olav Wulff. Flottenabteilung Wulff was sent through the mouth of the Danube and across the Black Sea to Odessa, where it spent several months supporting the Austro-Hungarian troops enforcing the peace agreement with Russia. They returned to the Danube at the end of August, and were anchored at Brăila on 12 September. On 16 October, she and the rest of the First Monitor Division sailed from Brăila to Belene. The Danube Flotilla then protected Austro-Hungarian troops withdrawing towards Budapest, fighting French and irregular Serbian forces as they withdrew, and arrived on 6 November.

Interwar period and World War II
Körös was temporarily manned by the Yugoslavs between 1918 and 1919, but was officially handed over to the Royal Yugoslav Navy and renamed Morava in 1920. Morava was scuttled by her crew on 11/12 April 1941 during the German-led Axis invasion of Yugoslavia. She was subsequently raised and repaired by the navy of the Axis puppet state the Independent State of Croatia, in which she served as Bosna. She struck a mine and sank in June 1944.