Adolf IX of Berg

Adolf IX (c. 1280–1348) was Count of Berg from 1308, succeeding his childless uncle William I. He married Agnes of Cleves in 1312, gaining the Duisburg Rhine customs as her dowry.

A loyal supporter of Emperor Louis IV from 1314, he attended his coronation in Rome and joined the English alliance against France. He continued Berg's feuds with the Archbishops of Cologne, and died childless in 1348, when Berg passed to his niece Margaret of Ravensberg and her Jülich husband.