Stem duchy

A stem duchy (German: Stammesherzogtum, from , 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. The five stem duchies (sometimes also called "younger stem duchies" in contrast to the pre-Carolingian tribal duchies) were Bavaria, Franconia, Lotharingia, Saxony and Swabia (Alamannia). The Salian emperors (reigned 1027–1125) retained the stem duchies as the major divisions of Germany, but already during the reign of Hohenstaufen emperors (reigned 1138–1254), the process of their dissolution was formalized, leading to divisions of traditional stem duchies into smaller and more numerous territorial duchies.

The term Stammesherzogtum as used in German historiography dates to the mid-19th century, and from the beginning was closely related to the question of national unification. The term's applicability, and the nature of the stem duchies in medieval Germany, consequently have a long history of controversy.

The overly literal or etymologizing English translation "stem duchy" was coined in the early 20th century. While later authors tend to clarify the term by using the alternative translation "tribal", use of the term "stem duchies" has become conventional.