In late September both the League and the Ottoman Empire mobilised their armies. Montenegro was the first to declare war, on 25 September (O.S.)/ 8 October. The other three states, after issuing an impossible ultimatum to the Porte on 13 October, declared war on Turkey on 17 October. The Balkan League relied on 700,000 troops, 370,000 of whom were Bulgarians. Bulgaria, often dubbed "the Prussia of the Balkans", was militarily the most powerful of the four states, with a large, well-trained and well-equipped army. The peacetime army of 60,000 troops was expanded during the war to 370,000, with almost 600,000 men mobilized in total out of a population of 4,300,000. The Bulgarian field army consisted of nine infantry divisions, one cavalry division and 1,116 artillery units. Commander-in-Chief was Tsar Ferdinand, while the actual command was in the hands of his deputy, Gen. Mikhail Savov. The Bulgarians also possessed a small navy of six torpedo boats, which were restricted to operations along the country's Black Sea coast.