Agri Decumates

The Agri Decumates or Decumates Agri ("Decumatian Fields") were a region of the

Claudius Ptolemy does mention "the desert of the Helvetians" in this area.^[3]

The meaning of Decumates is lost and has been the subject of much contention. According to the English Classicist

Michael Grant, the word probably refers to an ancient Celtic term^[4] indicating the political division of the area into "ten cantons." Another theory is that the term implies that a tithe was paid by residents living in this country.^[5]

According to Tacitus, the region was originally populated by the Celtic tribe of the Helvetii, but soon Germanic and Gaulish settlers arrived. Tacitus writes that:

I should not reckon among the Germanic tribes the cultivators of the tithe-lands [agri decimates], although they are settled on the further side of the Rhine and Danube. Reckless adventurers from Gaul, emboldened by want, occupied this land of questionable ownership. After a while, our frontier having been advanced, and our military positions pushed forward, it was regarded as a remote nook of our empire and a part of a Roman province.^[2]

Under the

Flavian and later emperors, Romans took control and settled the region.^[2] They built a road network for military communications and movements, and improved protection from invading tribes using the region to penetrate into Roman Gaul. Frontier fortifications (limes) were constructed along a line running Rheinbrohl—Arnsburg—Inheiden—Schierenhof—Gunzenhausen—Pförring (Limes Germanicus

).

The larger Roman settlements were Sumolecenna (

Ladenburg) and Arae Flaviae (Rottweil

).

Romans controlled the Agri Decumates region until the mid-3rd century, when the emperor Gallienus (259–260) evacuated it before the invading Alemanni and the secession of much of the Western Roman Empire under the "usurper and ruler" Postumus.^[6]

The Emperor

Probus' death (282), the region was finally given up and the Alemanni took control.^[7] Germanic peoples have continuously inhabited the region since then.^[1]

However, Roman settlements were not immediately abandoned. There is evidence the Roman way of life continued well into the 5th century, much as Roman patterns continued in neighboring Gaul long after the Western Roman Empire's collapse.

J. G. F. Hind has suggested

Saar, between Mainz and Metz

.

Notes

^ ^a ^b M. Grant, A Guide to the Ancient World, p. 17
^ ^a ^b ^c Tac. Ger. 29.
^ Ptolemy's Geography — Book II, Chapter 10
^ J. G. F. Hind, "Whatever Happened to the 'Agri Decumates'?" p. 188, where he links it to the Old Irish dechmad.
^ Smith, William (1854), Dictionary of Greek and Roman Geography
^ L. de Blois, The Policy of the Emperor Gallienus, p. 5, 250
^ D. Geuenich, Geschichte der Alemannen, p. 23
^ J. G. F. Hind, "Whatever Happened to the 'Agri Decumates'?", p. 189ff.