Lidzbark Warmiński was once the capital of Warmia and formerly its largest city. The city itself was a rich center of faith and culture in the Polish-Lithuanian Commonwealth and often it was known as the Pearl of Warmia. For a long period of time it was under the control of the Polish bishops and it was also a major economic center, only resigning its importance to the nearby city of Braniewo.
The Warmian Bishop's Castle is considered to be a great artistic and historical value in the world and has been recognised as a historical monument by the Polish government.
From 1933-45 Heilsberg was the site of the large German government radio station Transmitter Heilsberg. The town was heavily damaged after its conquest by the SovietRed Army during World War II in 1945. As part of territorial changes promulgated at the Potsdam Conference, the area was ceded to Poland and its ethnic German population was expelled to the west. The town, renamed Lidzbark Warmiński, was gradually resettled by Poles, many of them from the parts of eastern Poland annexed by the Soviet Union.