The definitive ethnography of the ancient Germans is Tacitus' Germania, in whose shadow all other subsequent Germanic ethnography inevitably stands. This is best read in an annotated edition, as the modern student will struggle with its various problems. But as ancient ethnography, it is an admirable work. Still, its influence and importance itself creates problems, as much of its terminology and cladistics has come to be applied to modern study of the Germanic ethnogenesis, but with inevitable evolution and adjustment of meaning and usage to suit our modern understanding. The consequence being, one cannot assume that, when a modern linguist refers to the "Istvaeonic" peoples, he is referring to the same peoples Tacitus refers to, as the "Istvaeones" (as in this case, a relationship cannot be demonstrated, though it is possible). Nonetheless, while linguistic evidence is our best contemporary tool by which to reconstruct from surviving evidence a Germanic origin/migration story over the broader historical scope, Tacitus offers the most trustworthy accounting of his era we can wish for. And it is an era of central importance, given that it is just a few hundred years before Germanics will begin telling their own story, and immediately prior to the time wherein the earliest Germanic inscriptions begin to appear.