“She was outclassed in everything except bravery” In April 1915 the Russian empire was on the verge of entering Hungary, having taken the great fortress of Przemyśl. But in May a German-led surprise offensive cracked Russian lines, shattering entire armies and causing a 300-mile retreat in what was probably “the greatest victory of World War I by the Central Powers”. Nearly one million prisoners were taken. Moscow lost the ruins of Przemyśl and all of Poland. For the next two years Russia will struggle but ultimately lose, tsardom falling to revolutions and the rise of the Soviet state.
More links: a British documentary on YouTube (start with Part 1), three photos of the German and Austrian advance, the New York Times for that week, the German commander describing the initial attack, a balanced account from a British observer, a 1915 book and its 1916 sequel.