monasteries and monastic foundation as tools in spreading his authority and in developing his regional economy by employing the industry of monks for secular benefit. Alsace was first spoken of as a in the 730s, though the correspondence of Alsace with the territory of the early can be inferred quite easily (for example, known dukes of Alsace referring to earlier dukes as their predecessors can only mean that the territorial unit of rule was the same). The term , "Duchy of Alsace", only came into use under Louis the Pious, though there exists disputed evidence of its use as early as 735–737. Later history Following the suppression of the Alemanni in 742–746 by Carloman, son of Charles Martel, the duchy of Alsace was dissolved in 742 when a successor for the deceased Duke Liutfrid was not named. While some historians have suggested an antipathy between the Etichonids and the Arnulfings to explain the dissolution of their power in Alsace, the Etichonids were allied with Charles Martel as early as the 720s, when he campaigned against the Alemanni, who were a constant thorn in the side of their Alsatian cousins. Some have interpreted the tripartite web of support between Alsatian monasteries, the Etichonid dukes and counts, and Theuderic IV as evidence of an attempt to stay outside of Arnulfing (subsequently Carolingian) control. In 722, Martel first defeated the Alemanni and in 744 some rebellious Alemans invaded Alsace, implying that it was considered loyal to Martel's successors, Carloman and Pepin the Short. Even Liutfrid himself may have died fighting on behalf of the Carolingians against the Alemanni. In any case, the peaceful dissolution of the duchy in Alsace mirrored the similar efforts of the Carolings elsewhere (notably Provence), while it was also part of a larger effort — which was notably violent in Alemannia and Aquitaine — to replace dukes, who had the power to command armies, with counts, who were royal officers responsible to and representative of royal power. Alsace remained a distinct unit after 742. With the rise in influence of Hugh of Tours, who was a conscious ancestor of the Etichonid dukes, Louis the Pious first made reference to the ducatus alsicensi in 816, though it was still a ducatus without a dux. In 829, Louis's youngest son, Charles, was made duke of Alsace, Alemannia and Rhaetia, but in 831 his share of the empire was expanded and was