Rhine-Weser Germanic peoples in the context of Weser–Rhine Germanic

The Chatti were a Roman era Germanic people that lived in a region approximately corresponding to the modern German federal state of Hesse. The Chatti were among the most important opponents of the Roman empire during the Roman campaigns in Germania which were pursued under the emperor Augustus and his heirs. In this context they were among the defeated opponents of Drusus the Elder, during his Germanic campaigns from 12 BC until his death in 9 BC. Subsequently, they also appear to have been involved in the revolt against Rome which was led by Arminius of the Cherusci, although there is no record of them being present at the Battle of the Teutoburg Forest in 9 AD which initiated these wars. The Chatti and Cherusci nobility were connected by marriage during this period.

Like many of the peoples of their region, archaeological evidence shows that before the Roman invasions the Chatti region shared in the La Tène material culture, similar to the Celtic-speaking Gauls in what is now France. A new regional "Rhine-Weser" material culture developed during the first century AD, which was influenced by both the Romans, and the Elbe Germanic peoples including the Suebi who lived to their east, near the Elbe river. This period of change is believed to have also involved a switch from Celtic to Germanic languages, which also originated near the Elbe. The first surviving Roman reports of the region were made during the Gallic Wars of Julius Caesar in 58-52 BC, do not mention the Chatti, but they do mention the entry of Suebi into the area. He reported them to be mobile and militarized, and creating major disruptions as far away as present day France and Switzerland, even forcing populations to move from their homelands.

Weser–Rhine Germanic languages (or Rhine–Weser Germanic, German: Rheinweser-germanisch), sometimes also referred to as Istvaeonic languages, are a proposed Frank-related subgroup of the West Germanic languages which would in terms of modern languages unite both West Central German dialects and Low Franconian dialects including standard Dutch.

According to original versions of this proposal, introduced by the German linguist Friedrich Maurer (1898-1984), this subgroup descends from a distinct Frankish language, while the related ancestral languages of the so called Elbe Germanic dialects to the south, and North Sea Germanic languages to the north, only subsequently became smoothly connected within the same dialect continuum. Maurer's proposals were influenced not only by linguistic evidence, but also by the Germanic archaeological provinces defined by Raphael von Uslar in 1938, which include the so called Rhine-Weser Germanic peoples, and by early Roman era reports of the Istvaeones – a group of Germanic peoples which lived near the River Rhine, and understood themselve to share a distinct common ancestry, according to their descriptions by Tacitus and Pliny the Elder.