Albert Frederick, Duke of Prussia (1553-1618), was a notable figure in the history of the {Duchy of Prussia}. He was the son of {Albert of Prussia}, the last Grand Master of the {Teutonic Knights}, and became the first Duke of Prussia after the region was secularized. His reign marked the transition of Prussia from a monastic state to a duchy under the Polish crown. During his rule, Albert Frederick focused on consolidating power and promoting economic development in his territory. He was known for his efforts to strengthen the {Protestant Reformation} in Prussia and for fostering cultural growth, which laid the groundwork for future advancements in the region.