The Alemanni (also Alamanni; Suebi "Swabians") were a confederation of Germanic tribes on the upper Rhine river. First mentioned by Cassius Dio in the context of the campaign of Caracalla of 213, the Alemanni captured the Agri Decumates in 260, and later expanded into present-day Alsace, and northern Switzerland, leading to the establishment of the Old High German language in those regions.
In 496, the Alemanni were conquered by Frankish leader Clovis and incorporated into his dominions. Mentioned as still pagan allies of the Christian Franks, the Alemanni were gradually Christianized during the 7th century. The Pactus Alamannorum is a record of their customary law during this period. Until the 8th century, Frankish suzerainty over Alemannia was mostly nominal. But after an uprising by Theudebald, Duke of Alamannia, Carloman executed the Alamannic nobility and installed Frankish dukes. During the later and weaker years of the Carolingian Empire the Alemannic counts became almost independent, and a struggle for supremacy took place between them and the Bishopric of Constance. The chief family in Alamannia was that of the counts of Raetia Curiensis, who were sometimes called margraves, and one of whom, Burchard II, established the Duchy of Swabia, which was recognized by Henry the Fowler in 919 and became a stem duchy of the Holy Roman Empire.
The area settled by the Alemanni corresponds roughly to the area where Alemannic German dialects remain spoken, including German Swabia and Baden, French Alsace, German-speaking Switzerland and Austrian Vorarlberg. Their name has survived into modern times, as in the French word for Germany, "Allemagne", or the Spanish word Alemania, or its Turkish counterpart, "Almanya"....LESS