Tannenberg, Battle of

Victory of a combined Polish and Lithuanian army over the Knights of the Teutonic Order in 1410, at Tannenberg, a village in northern Poland (now Grunwald). The battle broke the Knights' hold over Old Prussia (approximately modern Poland); their defeat led to the Treaty of Thorn and to an independent Polish state.

The Teutonic Knights were originally formed during the Crusades, and later undertook the conversion and conquest of Old Prussia. Eventually the Teutonic Knights took control of Poland, responsible to nobody other than the Pope, but their rule was oppressive and in 1410 the population, led by King Władysław Jagiełło, Grand Duke of Lithuania and king of Poland, rose against them. Władysław led an army of 20,000 to meet some 15,000 Knights near Tannenberg and completely defeated them, slaughtering several thousand Knights.

Tannenberg, Battle of

In World War I, victory of German forces led by field marshal Paul von Hindenburg over Russian forces under General Aleksander Samsonov in August 1914 at a village in East Prussia (now Grunwald, Poland) 145 km/90 mi northeast of Warsaw.

Hindenburg was waiting for Samsonov's attack, resisted it, turned the Russian left flank, and drove him back to Hohenstein. The Russians attempted to make a stand there but were driven into retreat. Hindenburg now extended his left flank through Allenstein, with the intention of encircling Samsonov and driving a wedge between him and General Paul Rennenkampf who was approaching from the north. He surrounded Samsonov on three sides at Tannenberg, the fourth being swamps and lakes, and destroyed his army; only about 60,000 troops managed to escape back to Russia. The Germans took 90,000 prisoners and several hundred guns. Hindenburg then struck north against Rennenkampf who wisely retreated to his base on the Niemen River line.