Osowiec Fortress

The fortress was built in the years 1882–1892 as one of the defensive works to protect the western borders of Russia against Germany, and continuously modernised afterwards to cope with advances in heavy siege artillery.

The fortress saw heavy fighting during the beginning of World War I in the eastern front from September 1914 until the Russian Army abandoned it in August 1915.

[3][4] Attempting to cut the railway line between Białystok and Warsaw, the Germans attacked the Osowiec fortress, which was lightly defended by a few Russian battalions.

[5] It is sometimes incorrectly claimed that Russian counter-battery fire destroyed two German heavy mortars; these guns were withdrawn for operations elsewhere.

[6] The Germans launched a full frontal offensive on the fortress at the beginning of July; the attack included 14 battalions of infantry, one battalion of sappers, 24–30 heavy siege guns, and 30 batteries of artillery equipped with poison gases led by Field Marshal Paul von Hindenburg.

The Germans waited until 04:00 on 6 August for favourable wind conditions, when the attack opened with regular artillery bombardment combined with chlorine gas.

The Russian garrison suffered heavy losses, but some soldiers survived even after the final charge, and chlorine gas barrage.

This offensive by the remaining Russian troops was dubbed the "Attack of the Dead Men", as the near deceased soldiers resembled the undead, still charging despite being badly injured.

[9] In 1953, the fortress was regarrisoned by a Polish Air Force ammunition depot,[9] which was absorbed into the 11th Regional Materiel Base in 1998.