Within East Francia were large duchies, sometimes called kingdoms ("regna") after their former status, which had a certain level of internal solidarity. Early among these were Saxony and Bavaria, which had been conquered by Charlemagne, and Alamannia, placed under Frankish administration in 746. In German historiography they are called the "jüngere Stammesherzogtümer", or "more recent tribal duchies", although the term "stem duchies" is common in English. The duchies are often called "younger" (newer, more recent, etc.) in order to distinguish them from the older duchies which were vassal-states of the Merovingian monarchs. Historian Herwig Wolfram denied any real distinction between older and younger stem duchies, or between the stem duchies of Germany and similar territorial principalities in other parts of the Carolingian empire: