In 1251, the Bishop of Warmia received a wooden stronghold in the strategic place called Lecbarg, and later Heilsberg, from the Teutonic Knights. The castle of Lidzbark was built between the rivers Łyna and Symsarna during the years 1350-1401.
During the years 1350 – 1795, it was the seat of the Bishops of Warmia and the castle had numerous prominent residents such as Nicolaus Copernicus and Bishops: Łukasz Watzenrode, Jan Dantyszek, Stanisław Hozjusz, Marcin Kromer, Jan Andrzej Chryzostom Załuski, Stefan Wydżga, Adam Stanisław Grabowski and Ignacy Krasicki. In 1589-1599, Bishop Andrzej Batory added a palace called the “rooms of cardinals" to the castle (pulled down in 1767). Further expansion took place during the times of Bishop Jan Stefan Wydżga who ordered building a baroque palace (1666-1673) along the south wing of the castle according to the design by the Italian architect, Issidore Affaiti. During late 1838 and 1839 the palace of Bishop Wydżga became neglected (currently its foundations only can be seen in front of the entrance to the castle). During the 19th c. the castle was used as the orphanage and hospital. After the World War II the castle was restored and as of January 1, 1963 has been branch of the Muzeum Warmia and Mazury in Olsztyn.
The castle of Lidzbark Warmiński is a jewel of gothic architecture with its unique preservation status, the Gothic cloisters and the polychromies dating back to the times of Bishop Henryk Sorbom (1373-1401) uncovered recently during conservation works. The paintings cover all the walls of the gallery on the first floor and 75 percent of them are legible. The example is the scene of Saint Catherine with Saints Diorite and Barbara. Another impressive polychromy from 1380, representing the scene of Coronation of Virgin Mary, can be seen in the impression gothic hall of the Grand Refectory.
The rococo chapel of St. Catherine of Alexandria representing the amazing wealth of ornaments and accumulation of works of art from the 17th and 18th century should also be seen.
The castle has a massive tower in the north-eastern corner. Gothic cellars can also be visited. In appearance the castle resembles Teutonic castles. The fortress had its own mill and a large forecourt, and the whole was surrounded by the moat.