The Angrivarii were a Germanic tribe of the early Roman Empire mentioned briefly in Ptolemy as the Angriouarroi (Ancient Greek: Ἀνγριουάρροι), which transliterates into Latin Angrivari. They are believed to be the source of the 8th century identity, Angrarii, which was one of three subdivisions of Saxony (the others were Westfalahi and Ostfalahi). The name appears earliest in the Annales and Germania of Tacitus as Angrivarii.
In post-classical times the name of the people had a number of different spellings in addition to the ones just mentioned: Angarii, Aggeri, Aggerimenses, Angerienses, Angri, Angeri. They lived in a district called Angria, Angaria, Angeriensis, Aggerimensis and Engaria.
They lived in Engern, a region west of the Weser river not far from Teutoburg Forest, and also (probably by extension) in Angeron of Münster. Ancient Engern was a much larger district than today's community, comprising most of the country surrounding the middle Weser, including both flat land, as around Minden, and low hills (Holzminden). It became part of today's Westphalia.
The name Angrivarii can be segmented Angri-varii meaning "the men of Engern", parallel to Ampsi-varii, "the men of the Ems." Julius Pokorny derives the first element from an Indo-European root *ang-, "to bend, bow." From this root are also derived German Anger, English dialect ing, Danish eng, Swedish äng, Dutch eng/enk, and many other forms in Germanic languages, all meaning "meadow, pasture." Cf. the similar element Angeln.
The second element -varii is most prolific among Germanic tribal names, commonly taken to mean "inhabitants of", "dwellers in". Its precise etymology remains unclear, but there is a general consensus that it cannot be derived from the PIE root *wihxrós, "man", surviving in English "were-wolf".
Although the Angrivarii receive brief mention in Ptolemy (2.10) and the Germania of Tacitus (33), they appear mainly at several locations in Annales. They were involved marginally in the wars fought by the talented Germanicus Caesar on behalf of his uncle Tiberius, emperor of Rome, against the perpetrators of the massacre of three Roman legions in the Battle of the Teutoburg Forest, the year 9.
The wars began in the last years of the reign of Augustus, first emperor of Rome. Augustus died an old but respected man in the year 14 and was celebrated with much pomp and splendor. He left a document to be read to the senate posthumously, expressly forbidding extension of the empire beyond the Rhine. News of the will was welcomed by the Germans, thinking it gave them a free hand in the region. Germanicus found it necessary to pacify the border, which he did by a combination of scorched earth raids and offers of alliance with Rome - in short, stick and carrot. These raids also kept the army of the lower Rhine distracted from the possibility of mutiny, which had broken out on Augustus's death and only been quelled by concessions and executions.
For punitive expeditions Germanicus used the Ems river, which flowed from the heart of the country occupied by the tribes that became the Franks. These were still under Arminius, who had led the German confederation to the victory in 9. Unlike Arminius' native tribe, the Cherusci, the loyalty of the other tribes in the confederation was at best equivocal.
The Angrivarii's defection or revolt (defectio) in the middle of Arminius's renewed operations against the Teutoburg Forest must have been secured in advance by Germanicus. Even if it was not, a cavalry attack soon brought the Angrivarii's capitulation. Soon afterwards, however, they are back in alliance with the Cherusci and opposition to the Romans, setting an ambush at the Cheruscan border, which was a high dirt embankment. They hid their cavalry in the woods and stationed their infantry on the reverse slope of the bank. The Romans had intelligence of the plan beforehand. They assaulted the embankment, preceding their assault with volleys from slings and spears thrown by machines. Driving the Angrivarii from the bank, they went on to pursue the cavalry in the woods. Once again the Angrivarii were totally routed.
Once the Cherusci had been dealt with, Germanicus turned his attention to the Angrivarii. They, however, surrendered unconditionally to the general sent by Germanicus and placed themselves in the status of suppliants, begging for mercy, which Germanicus granted. This later reaped dividends for the Angrivarii played a major role in securing the return of ships and men lost in a North Sea storm which scattered the Roman fleet upon the shore of hostile or neutral Germanic tribes.
Finally, on May 26 of the year 17, Germanicus celebrated a triumph for his victory over lower Germany and his uncle sent him off to the east. Arminius died and the Angrivarii, the other west Germans and their successor tribes continued friendly towards Rome, providing it with elite troops and urban and palace police.