Aleksey Alekseyevich Brusilov (; – 17 March 1926) was a Russian general most noted for the development of new offensive tactics used in the 1916 Brusilov Offensive, which was his greatest achievement. The innovative and relatively successful tactics used were later copied by the Germans. Born into the aristocracy to a father who was also a general, Brusilov trained as a cavalry officer, but by 1914 he realized that cavalry was obsolete in the new style of warfare because of its vulnerability to machine gun and artillery. Historians portray him as the only First World War Russian general capable of winning major battles. However, his heavy casualties seriously weakened the Russian army, which was unable to replace its losses.