During the First World War, Galicia saw heavy fighting between the forces of Russia and the Central Powers. The fighting began in 1914 when the Russian Army advanced into the Austro-Hungarian province of Galicia and German East Prussia. The initial attack on East Prussia quickly turned into a defeat following the Battle of Tannenberg in August 1914 but the second incursion was completely successful. Under the command of generals Nikolai Ivanov and Aleksei Brusilov, the Russians won the Battle of Galicia in September and began the Siege of Przemyśl, the next fortress on the road towards Kraków. By the end December 1914, the Russians controlled almost all of Galicia. However the victory was short-lived, the Russians were pushed out of Galicia in the spring and summer of 1915 by a combined German, Austro-Hungarian and Turkish offensive.