The German kings and emperors ruled the Netherlands in the 10th and 11th century, with the assistance of the Dukes of Lotharingia, and the bishops of Utrecht and Liège. Germany was called the Holy Roman Empire after the coronation of King Otto the Great as emperor. The Dutch city of Nijmegen used to be the spot of an important domain of the German emperors. Several German emperors were born and died there, including for example Byzantine empress Theophanu, who died in Nijmegen. Utrecht was also an important city and trading port at the time.