The establishment of the defence system and the armed forces as its most crucial element was among the most sensitive and demanding tasks during the formation of the State of Slovenes, Croats and Serbs. In October 1918, the risk involved in the political act of proclaiming an independent state dictated exceedingly tentative preparations. Therefore, as late as on the day when the new state was established, the state leadership started setting up the first elements of the defence system by adopting the former Austro-Hungarian defence system, including the legislation. Subsequently, it kept adapting and simplifying this system in accordance with the circumstances. Its management was distributed between the National Defence Commissions in Zagreb (the central Commission, in charge also of the Kingdom of Croatia), Ljubljana, and Sarajevo. The SHS National Council based its activities on the principle of a single defence system with a single army, consisting of three (later four) military commands for the Slovenian provinces, Kingdom of Croatia, Slavonia and Dalmatia and Bosnia and Herzegovina. With the administrative definition of its scope of activities after 19 November 1918, the National Government of SHS in Ljubljana assumed direct control over the military matters and the defence system and merged all three branches of the Austrian armed forces into unified armed forces, based on mobilisation (with many elements of voluntarism).