Germany–Poland relations refer to the bilateral relations between Germany and Poland. These relations have been marked by an extensive and complicated history. From the 10th century onward, the Piast-ruled Kingdom of Poland established under Duke Mieszko I had close and chequered relations with the Holy Roman Empire. However, these relations were overshadowed in the Late Middle Ages both by the push eastwards of the Margraviate of Brandenburg into Polish territory and the centuries-long Polish–Teutonic Wars, as a result of which the State of the Teutonic Order became a part and fief of the Kingdom of Poland, later transformed with the consent of the Polish King into the secular Duchy of Prussia. Prussia retained a certain level of autonomy under Polish rule. Later, the Kingdom of Prussia r