HEILSBERG, a town of Germany, in the province of East Prussia, at the junction of the Simser and Alle, 38 m. S. of Königsberg. Pop. (1905), 6042. It has an Evangelical and a Roman Catholic church, and an old castle formerly the seat of the prince-bishops of Ermeland, but now used as an infirmary. The principal industries are tanning, dyeing and brewing, and there is considerable trade in grain. The castle founded at Heilsberg by the Teutonic order in 1240 became in 1306 the seat of the bishops of Ermeland, an honour which it retained for 500 years. On the 10th of June 1807 a battle took place at Heilsberg between the French under Soult and Murat, and the Russians and Prussians under Bennigsen.