After an eight-day offensive that marked the beginning of a new, aggressive strategy in the region, Austro-Hungarian troops under commander in chief Franz Conrad von Hotzendorf take control of the Balkan state of Montenegro.
By the end of 1915, after initial setbacks, the Central Powers had completed their conquest of Serbia, the upstart Balkan country that they claimed had provoked the war in June 1914, when a Serbian nationalist had assassinated Austrian Archduke Franz Ferdinand. Despite their success in the Balkans, Conrad was incensed that the victories had been achieved largely by German, not Austrian, forces. He opposed the establishment of a joint German-Austrian command in the region, fearing, with reason, that Austria would be subordinated to its stronger ally. Relations between Conrad and his German counterpart, Erich von Falkenhayn, who sought to turn German energies more fully toward France and the Western Front, had become so strained that they ceased direct communication almost entirely for a full month from December 1915 to January 1916. During that time, Conrad proceeded to develop Austria's strategy for early 1916, which was to capture Montenegro in the winter and then turn toward Italy with an attack in the Trentino.
On January 8, 1916, with a 500-gun artillery barrage, 45,000 Austrian troops and 5,000 Bosnian Muslims attacked Serbia's ally, the neighboring state of Montenegro. Events unfolded quickly: Within 48 hours, the Montenegrins had retreated to their capital, Cetinje, after being driven from their fortresses at Mount Lovcen on the Adriatic Sea. Cetinje fell on January 11 and the end was already in sight. Montenegro surrendered on January 16. When her emergency came, there was no one to help her, the American diplomat John Coolidge wrote of Montenegro, so she had to go.