Douglas Harper's Etymology Dictionary
name of a Suebic tribe or confederation that settled in Alsace and part of Switzerland (and source of French Allemand "German, a German"), from Proto-Germanic *Alamanniz, probably meaning "all-man" and denoting a wide alliance of tribes, but perhaps meaning "foreign men" (compare Allobroges, name of a Celtic tribe in what is now Savoy, in Latin literally "the aliens," in reference to their having driven out the original inhabitants), in which case the al- is cognate with the first element in Latin alius "the other" and English else.
Wikipedia
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.
Usage examples of "alemanni".
Strangely enough, the Alemanni preferred to camp on the outskirts or, even better, in the surrounding woods and fields.
The ferocity of their charges was astonishing, and at the time, Brother, I could scarcely believe that actual battle with the Alemanni could have been any more brutal.
It was inconceivable that the Alemanni could have strayed so far from their Rhone forests, for Autun was a good hundred miles from the previous limits of their invasions.
This time, however, his troops faced the full brunt of an Alemanni force that attacked them on the way.
For too long, soldiers, the Alemanni have failed to feel the fury and the might of the Roman army.
We have marched from Vienne to Autun, from Auxerre to Troyes, routing the Alemanni and reclaiming Gaul for Rome and the Emperor.
With almost bewildering speed and precision, he divided his forces to lure the Alemanni into indefensible valley positions, where they were surrounded.
Empire against the Alemanni massing on the far side of the Rhine that he had neglected his own base of operations.
I peered over the walls that morning I surveyed ten thousand Alemanni massing just out of our arrow range, their officers racing and prancing up and down the lines on their horses.
He forced himself to study the maneuvers of the attackers, occasionally commenting to Sallustius on the discipline and arrangement of the Alemanni forces.
With thundering, slashing hooves, a squad of torch-wielding Alemanni cavalry plunged toward the open door, followed by a mob of howling infantry, their bodies naked and streaked with flame-colored paint, like that of their barbarous leader.
There, a number of recent raids by Alemanni on local farms and villages seemed to foretell a larger, better-planned movement by Chonodomarius in the near future.
A soldier told me the Alemanni had scuttled it in a swamp nearby, but Barbatio had ordered it raised and patched.
Cornuti tribune who had defeated the Alemanni river raiders a few weeks earlier, scoffed.
If we flee instead, then it is not only the Alemanni massing along the Rhine who will pour into Gaul, but every middling tribe from the Alps to the northern sea and from the Rhine to the Black Forest will pour out their hidden valleys and caves and rush like floodwaters into our cities.