Adolf I, Count of Nassau-Siegen

Count Adolf I of Nassau-Siegen, German: Adolf I. Graf von Nassau-Siegen, was since 1384 Count of Diez, through his first marriage. With his brothers, he succeeded his father in 1416 as Count of Nassau-Siegen, and also inherited the County of Vianden in 1417. He descended from the Ottonian Line of the House of Nassau.