 The army's development was hampered by the kingdom's poor economy, and this continued through the 1920s. In 1929, King Alexander changed the name of the country to the Kingdom of Yugoslavia, at which time the army was renamed the Royal Yugoslav Army (Serbo-Croatian: Vojska Kraljevine Jugoslavije, VKJ). The army budget remained tight, and as tensions rose across Europe during the 1930s, it became difficult to secure weapons and munitions from other countries. Consequently, at the time World War II broke out in September 1939, the VKJ had several serious weaknesses, which included reliance on draught animals for transport, and the large size of its formations. For example, infantry divisions had a wartime strength of 26,000 – 27,000 men, as compared to contemporary British infantry divisions of half that strength. These characteristics resulted in slow, unwieldy formations, and the inadequate supply of arms and munitions meant that even the very large Yugoslav formations had low firepower. Older generals better suited to the trench warfare of World War I were combined with an army that was not equipped or trained to resist the fast-moving combined arms approach used by the Germans in their invasions of Poland and France.
