The Electors of Brandenburg were powerful rulers in the Holy Roman Empire, specifically in the region of Brandenburg, which is now part of modern-day Germany. They played a crucial role in the political landscape of the empire from the late Middle Ages until the 19th century. The title of elector granted them the right to participate in the election of the Holy Roman Emperor. The most notable elector was Frederick III, who later became Frederick I of Prussia. Under his leadership, the Margraviate of Brandenburg expanded its influence, eventually leading to the establishment of the Kingdom of Prussia. The electors were instrumental in shaping the history and governance of the region.