By 1400 the long running conflict between the Teutonic Knights and the Polish-Lithuanian kingdom was coming to a head. In June 1410 Ladislos II of Lithuania invaded the Order's territory with an army of 10,000. It included many of the Teutonic Knights enemies - Poles, Lithuanians, Russians, Tartars and Cossacks. The armies clashed on the rolling hills of Tannenberg, although neither side could gain any decisive advantage. The Hochmeister then led his remaining reserve against the Lithuanian King's contingent in an attempt to pierce the enemy line. His charge failed and he and many of the Order's leading officer's were surrounded and killed. The Teutonic Knights never recovered from this disastrous defeat, which marked the beginning of a terminal decline in this once great Order.