The Yugoslav Army (Serbo-Croatian: Jugoslovenska vojska, JV, Југословенска војска, ЈВ), commonly the Royal Yugoslav Army, was the principal ground force of the Kingdom of Yugoslavia. It existed from the establishment of Yugoslavia in December 1918 until its surrender to the Axis powers on 17 April 1941. Aside from fighting along the Austrian border in 1919 and 1920 related to territorial disputes, and some border skirmishes on its southern borders in the 1920s, the JV was not involved in fighting until April 1941 when it was quickly overcome by the German-led invasion of Yugoslavia.
Shortly before the invasion, Serbian officers of the Yugoslav General Staff, encouraged by British Special Operations Executive personnel in Belgrade, led a coup d'état against Prince Paul of Yugoslavia and Dragiša Cvetković for adhering to the Tripartite Pact. Beyond the problems of inadequate equipment and incomplete mobilization, the Royal Yugoslav Army suffered badly from the Serbo-Croatian schism in Yugoslav politics. Yugoslavian resistance to the Axis invasion collapsed overnight, primarily due to a large part of the non-Serb population, Croats in particular, being unwilling to offer resistance. In its worst expression, Yugoslavia's defenses were badly compromised on 10 April 1941, when some of the units in the Croat-manned 4th and 7th Armies mutinied, and a newly formed Croatian government hailed the entry of the Germans into Zagreb the same day.
