The Duchy of Lorraine was a principality of the Holy Roman Empire which existed from the 10th century until 1766 when it was annexed by the Kingdom of France. It gave its name to the larger present-day region of Lorraine in northeastern France. Its capital was Nancy.
It was founded in 959 following the division of Lotharingia into two separate duchies: Upper and Lower Lorraine, the westernmost parts of the Holy Roman Empire. The Lower duchy was quickly dismantled, while Upper Lorraine came to be known as simply the Duchy of Lorraine. The Duchy of Lorraine was coveted and briefly occupied by the dukes of Burgundy and the kings of France, but was ruled by the dukes of the House of Lorraine after 1473.