Stem duchy
A stem duchy (German: Stammesherzogtum, from Stamm, meaning "tribe", in reference to the Franks, Saxons, Bavarians and Swabians) was a constituent duchy of the Kingdom of Germany at the time of the extinction of the Carolingian dynasty (death of Louis the Child in 911) and through the transitional period leading to the formation of the Ottonian Empire. The Carolingians had dissolved the original tribal duchies in the 8th century, but as the Carolingian Empire declined during the 9th century, the old tribal areas assumed new identities.