United Duchies of Jülich-Cleves-Berg
After ten years their only child was born, a girl named Maria. She married Duke John III of Cleves. They were engaged in 1496, when Maria was five years old and John was six. They married in 1510. This resulted in the so-called "Cleves Union" in which the Duchies of Jülich-Berg-Ravensberg and Cleves-Mark were combined to form the United Duchies of Jülich-Cleves-Berg. When William died in 1511, Maria, being female, could not inherit and Jülich-Berg-Ravensberg fell to John III.