Page "History of Belgium" Paragraph 9

Caesar reported that the northern Belgae, approximately in the area of modern Belgium, were less economically developed, and militarily dangerous people, similar to the people east of the Rhine river.

He referred to both these groups as Germani.

The area was still marked by dense forests, swamps and other types of wilderness.

There is also less evidence of large settlements and trade.

In fact, Caesar was informed that a large part of the Belgae had Germanic ancestry, and in particular the Belgae living in the area stretching from eastern Belgium to the Rhine were referred to by Caesar as the Germani cisrhenani.

According to Tacitus, writing a generation later, these were in fact the original tribe to be called Germani, and all other uses of the term extended from them.

Modern linguists use the word " germanic " to refer to people speaking Germanic languages and it is possible that all or part of the Belgae were Germanic in this sense.

On the other hand it is not known for sure whether even the Belgian Germani spoke a Germanic language, and their tribal and personal names are clearly Celtic.

This is in fact also true of the possibly related tribes across the Rhine from them at this time.

Archaeologists have had difficulty finding evidence of the exact migrations from east of the Rhine which Caesar reports and more generally there has been skepticism about using him in this way due to the political motives of his commentaries.

But there is a general impression that the Belgae were a relatively stable population going back to Urnfield times, but with a much more recently immigrated elite class who would have been of more interest to Caesar.