The castle in Rydzyna was built at the beginning of 15th. century by Jan of Czernina. At the end of 17th. century Italian architects Joseph Simon Bellotti and Pompeo Ferrari erected the present Baroque castle on its ancient foundations. First owners of the castle were the Leszczyński family. Together with park and surrounding areas, it was one of the most splendid palaces in Great Poland. 1704-1709 a residence of Polish king Stanisław Leszczyński. 1709, during the Great Northern War, the castle was partly burnt by tsar's soldiers. However wall-paintings and stucco works in representative rooms, made by best Italian artists, were not destroyed completely. Stanislaw Leszczynski was forced to abdicate and exiled to France. After years, as Duke of Lorraine, he famed as charitable and wise sovereign. His daughter Maria became queen of France and mother of King Louis XVI.
Stanisław Leszczyński sold his estates in Poland to Aleksander Joseph Sułkowski. The new owner improved the castle. The Silesian architect Karl Martin Frantz changed roofs, added Rococo decorations and the monumental main gate. He also rebuilt the parish church and the town. The son of Aleksander Joseph, Prince August, continued the expansion. Classical ornamentation was added to the the Ballroom. The outbuildings and Orangerie were added to the north of the palace. At the end of 18th. century the residence of the Sułkowski princes, with open-air theater and high school of Piarist Fathers, was the most important cultural and educational centre in Great Poland.
After the second partition of Poland in 1793, the architectural development in Rydzyna ceased. Two of the Sułkowskis of Rydzyna were covered with glory: brave and talented Joseph Sułkowski, the aide-de-camp of Napoleon, killed in action at Cairo and his cousin Anthony Paul - the fourth Sułkowski owner of Rydzyna - whose name is inscribed on the Arch de Triomphe in Paris. The last Prince Sułkowski died childless in 1909. The Castle was taken over by Prussian authorities. In 1919 the Versailles Treaty gave it back to Poland. In accordance with the statutes of the Sulkowski family that had been established by Prince August in 1775 with the approval of the Polish Parliament, the Educational Foundation of the Sulkowski family was restored in 1924. In 1928 boarding school for boys- the Sułkowski School, was established under the direction of professor Tadeusz Łopuszanski, who had very interesting and innovative ideas about education.
During the German occupation, 1939-1945, a "Hitlerjugend" school was placed in the castle. At the end of January 1945 the Castle in Rydzyna was burnt. The severely damaged Castle awaited a new owner until 1970, when was taken over by The Association of Polish Mechanical Engineers (S.I.M.P.) and rebuilt according to documents and photographs from before World War II. The work was completed in 1989. In 1994 the castle was awarded by the prestigious international organization EUROPA NOSTRA in recognition of the excellence of the restoration work.
Original equipment and furnishing from the Castle were lost before World War I. The main Baroque rooms were completely restored to their original grandeur according to the historic documentation. In the castle collections there are: old furniture, historical drawings, remembrances of the Sułkowski family, nature collections e.g.: tropical butterflies, hunting trophies. In the library one can find documentation connected with the previous owners of the Castle, The Sulkowski Grammar School and The Association of Polish Mechanical Engineers.