Masuria Masuria comprised the southeastern portion of the German province of East Prussia, the part of the Reich that was most exposed to a threat from Russia. Two great battles took place here and immediately across the border in Russian Poland in 1914/15. The Russian Army occupied Masuria at the beginning of the war, and remained there until it was defeated at Tannenberg at the end of August 1914. After this battle the remnants of the Russian Second Army, which had entered Masuria from the south, withdrew across the border into Poland.…