largest diocese in Germany throughout the Merovingian and early Carolingian era. The dioceses of Alamannia, including Chur, which had been a suffragan of the Archdiocese of Milan, were placed under the jurisdiction of the Archdiocese of Mainz by the Carolingians. After the death of Dagobert I in 638, Alamannia, like Bavaria, Aquitaine, and Brittany, broke its ties with its Frankish sovereigns and struggled for independence. This was largely successful until the early 8th century, when a series of campaigns waged by the Arnulfing mayors of the palace reduced Alamannia to a province of Francia once again. It was, however, during this period of de facto independence that the Alamanni began to be ruled by one duke, though Alsace and Rhaetia remained outside of the scope of Alamannia. Between 709 and 712, Pepin of Heristal fought against Lantfrid, who appears as dux of the Alamanni, and who committed to writing the second Alamannic law code, the Lex Alamannorum. In 743, Pepin the Short and Carloman waged a campaign to reduce Alamannia and in 746 Carloman began a final thrust to subdue the Alamannic nobility. Several thousand Alamanni noblemen were summarily arrested, tried, and executed for treason at a Council at Cannstatt. Carolingian rule During the reign of Louis the Pious, there were tendencies to renewed independence in Alamannia, and the 830s were marked by bloody feuds between the Alamannic and Rhaetian nobility vying for dominion over the area. Following the Treaty of Verdun of 843, Alamannia became a province of East Francia, the kingdom of Louis the German, the precursor of the Kingdom of Germany. It was called a regnum in contemporary sources, though this does not necessarily mean that it was a kingdom or subkingdom. At times, however, it was. It was granted to Charles the Bald in 829, though it is not certain whether he was recognised as duke or king. It was certainly a kingdom, including Alsace and Rhaetia, when it was granted to Charles the Fat in the division of East Francia in 876. Under Charles, Alamannia became the centre of the Empire, but after his deposition, it found itself out of favour. Though ethnically singular, it was still plagued by Rhaetian-Alamannic feuds and fighting over the control of the Alamannic church. Alamannia in the late 9th century, like Bavaria, Saxony, and Franconia, sought to unite itself under one duke, but it had considerably less success than