On an island at the mouth of the Lake Drwęckie Drwęca existed Prussian castle, in the place probably in the second half of the thirteenth century was built by the Teutonic Knights watchtower. Initially, it was subordinated to the commander dzierzgońskiemu and officiated here Teutonic mayor. When the Order expanded its borders to the surrounding area Dziatdowo, Olsztynek and Nidzicy decided in 1341 years to create in Osterode self-Comtat.

Border location and the growing importance of Ostroda decided on the need to rise brick headquarters for the commander. In 1349 years commander Günter von Hohenstein started building long-lasting strongholds, but not in place of the guards. On stone foundations created regular quadrilateral brick castle with dimensions of 44.7 to 45.2 meters. Courtyard circulated wooden cloisters, and the east wing there was a tower-Stolp. Construction lasted no longer breaks during the years 1365-1380. In 1381 years, the castle was damaged during the invasion of Duke of Lithuania Kestutis. During this invasion was probably destroyed earlier Teutonic watchtower. After removal of the destruction of the castle was continued for another 1407 years to build. It is in this last stage of the construction of the castle received an additional outer defensive wall and a moat.

The four typical assumption had locks religious layout of rooms. On the lowest floors housed the utility rooms. In the south wing on the first floor housed the chapel, refectory and flat commander. The other wing on the higher floors have to include the chapter house, infirmary, dormitories and public houses. The highest tier fulfill the functions of defense and housed granaries.

Ostróda as one of the first Commandery was equipped with firearms. In 1391 years there were six guns equipped with a relatively large number of balls. The Order was aware of the great importance of Ostróda and before the outbreak and during the war of the Polish commanders Friedrich von Zollern and then Gamroth von Pintzenau were very well also in the food supply. However, in the Battle of Grunwald commander was killed and the castle remained modest manned by crew. With this fact, a small Prussian force under the command of Nicholas von Doringen unexpectedly struck on Ostródzka fortress and easily took over the castle and the city. Wladyslaw Jagiello gave the castle Janusz Mazowiecki, but September 19, 1410, he returned into the hands of the religious.

Shortly Teutonic Knights castle was stormed by the army of the Prussian Union in 1454, but after reflection it by knights on February 24 this year, remained in the hands of the Teutonic Knights. Yet in 1519 he was briefly in the hands of Polish to which he returned for good after the secularization of the Order in 1525.

The county was established here, and half of the sixteenth century it was some refurbishment work to adapt the castle to the royal court stays the way to Gdansk.

Until the mid-seventeenth century, little has changed, until the war with Sweden contributed to the further modernization of the castle. On Drwęca built airlock for lifting the water level in the moats, and the castle fortifications were strengthened bastion.

When in 1788 the castle and the town touched the fire erupted barrels of gunpowder in the basement of the east wing, which was completely destroyed, along with the tower. Castle is additionally affected because the reconstruction of the city population used the material from the damaged buildings of the castle. By the end of the eighteenth century but was rebuilt three wings castle allocating them to the district office and apartment.

Another war turmoil that swept through these areas is the Napoleonic wars. In 1806 the castle was used for the headquarters of German-Russian forces, but in 1807 Ostróda has been earned by Napoleon and the castle he placed his staff in the upcoming expedition deep into Russia. Napoleon himself stayed here for sure from 21 to 30 March 1807 year.

In the nineteenth century the castle was adapted to the needs of the court and government offices, some of the rooms still left for residential purposes.

At the end of 1945 years the castle was destroyed equipment caused by fighting the fire. The remaining fire damaged the walls of the wings, which

in 1974 it was decided to rebuild.

Today is the cultural center of the city.