The reorganization of the Belgian army that had begun in 1913 was only due to be completed in 1926. Consequently at the outbreak of war, the Belgian army was under-strength and largely unprepared. Albert I took personal command of the 265,000-strong Belgian army. However, they could do little against the 1.5 million-strong German invading force. Between August and October 1914, the Germans took the fortified cities of Liège, Namur and Antwerp and occupied Brussels. The fortified positions proved little match for the greatly improved siege artillery available to the Germans at the time, although the greater-than-expected defence did buy some time for the French and British to react. By the end of October, the Belgian army had been forced into a small pocket along the Yser river in the far west. In a surprising victory, the Belgian army managed to halt the German advance at the Yser, paving the way for the static trench warfare that which would characterize the Western Front for the next four years. Most of Belgium, however, was occupied by Germany and would remain under German control until 1918.