The
Duchy of Jülich (; ; ) comprised a state within the
Holy Roman Empire from the 11th to the 18th centuries. The duchy lay left of the
Rhine river between the
Electorate of Cologne in the east and the
Duchy of Limburg in the west. It had territories on both sides of the river
Rur, around its capital
Jülich – the former
Roman Iuliacum – in the lower
Rhineland. The duchy amalgamated with the
County of Berg beyond the Rhine in 1423, and from then on also became known as
Jülich-Berg.