Herzogtum Westfalen
The Duchy of Westphalia () was a historic territory in the Holy Roman Empire, which existed from 1102 to 1803. It was located in the greater region of Westphalia, originally one of the three main regions in the German stem duchy of Saxony and today part of the state of North Rhine-Westphalia. The duchy was held by the Archbishops and Electors of Cologne until its secularization in 1803.