Konrad I of Masovia
Konrad I of Masovia (ca. 1187/88[1] – 31 August 1247), from the Polish Piast dynasty, was the sixth Duke of Masovia and Kuyavia from 1194 until his death as well as High Duke of Poland from 1229 to 1232 and again from 1241 to 1243.
Konrad I
Konrad's legacy[edit]
Konrad is considered by Poles to be responsible for Teutonic Knights' control of most of the Baltic coastline, undermining Polish authority in the area. King Casimir III of Poland had to accept the rule of the Order in Thorn and Kulm by the 1343 Treaty of Kalisz. After the Thirteen Years' War in the 1466 Second Peace of Thorn, the Polish King Casimir IV Jagiellon gained control over the Chełmno Land as part of Royal Prussia.