In the 11th-13th century a Baltic Prussian stronghold was located at the Klasztorna Góra ("Monastery Hill"). The "terra Cadinensis" in Prussia was first mentioned in a 1255 deed. It was allegedly named after Cadina, a daughter of an Old Prussian chief. Actually Old Prussian "kudas" means "hardship" or "wilderness". Named "Kudien" in 1354, the Teutonic Knights of the Elbing commandry had built a "Vorwerk" estate near the site of a former Prussian fortress, where they held court over the native Pogesanian inhabitants in the area. From 1431 the Kadyny ("Cadinen") manor was owned by Jan Bażyński, leader and co-founder of the Prussian Confederation, upon the request of which Polish King Casimir IV Jagiellon incorporated the region to the Kingdom of Poland in 1454, and then Polish governor of the region, who fought on the Polish side during the subsequent Polish–Teutonic Thirteen Years' War. The over 700-years old Bażyński Oak, a natural monument, in Kadyny is named after Jan Bażyński.