#10: Jadwiga of Poland – About 10 years old
Jadwiga was crowned monarch of Poland in 1384 at around ten years old. To reinforce her authority, she was officially crowned “King” of Poland rather than “Queen,” removing any doubt about her right to rule. Two years into her reign, she married Jogaila, Grand Duke of Lithuania, who became King Władysław II Jagiełło. Jadwiga, however, remained an influential political figure. A devout and capable ruler, she strongly supported education and helped develop the University of Kraków. She also played a key role in the Christianization of Lithuania.
