The Germanic peoples were historical groups of people that once occupied Central Europe and Scandinavia during antiquity and into the early Middle Ages. Since the 19th century, they have traditionally been defined by the use of ancient and early medieval Germanic languages and are thus equated at least approximately with Germanic-speaking peoples, although different academic disciplines have their own definitions of what makes someone or something "Germanic". The Romans named the area in which Germanic peoples lived Germania, stretching East to West between the Vistula and Rhine rivers and north to south from Southern Scandinavia to the upper Danube. In discussions of the Roman period, the Germanic peoples are sometimes referred to as Germani or ancient Germans, although many scholars consider the second term problematic, since it suggests identity with present-day Germans. The very concept of "Germanic peoples" has become the subject of controversy among contemporary scholars. Some scholars call for its total abandonment as a modern construct since lumping "Germanic peoples" together implies a common group identity for which there is little evidence. Other scholars have defended the term's continued use and argue that a common Germanic language allows one to speak of "Germanic peoples", regardless of whether these ancient protagonists saw themselves as having a common identity.
Most scholars view the Jastorf Culture (6th century BCE to 1st century CE) in what is now Denmark and northeastern Germany as the earliest material evidence for the Germanic peoples' existence. Roman authors first described Germanic peoples near the Rhine in the 1st century BCE, while the Roman Empire was establishing its dominance in that region. Under Emperor Augustus (63 BCE-14 CE), the Romans attempted to conquer a large area of Germania, but they withdrew after a major Roman defeat at the Battle of the Teutoburg Forest in 9 CE. The Romans continued to control the Germanic frontier closely by meddling in its politics, and they constructed a long fortified border, the Limes Germanicus. From 166 to 180 CE, Rome was embroiled in a conflict against the Germanic Marcomanni, Quadi, and many other peoples known as the Marcomannic Wars. The wars reordered the Germanic frontier, and afterwards, new Germanic peoples are heard of such as the Franks, Goths, Saxons, and Alemanni. During the Migration Period (375–568), various Germanic peoples entered the Roman Empire and eventually took control of parts of it and established their own independent kingdoms after the collapse of Western Roman rule. The most powerful of them were the Franks, who would conquer many of the others. Eventually, the Frankish king Charlemagne would claim the title of Roman emperor for himself in 800.
Archaeological finds suggest that Roman-era sources portrayed the Germanic way of life as more primitive than it actually was. Instead, archaeologists have unveiled evidence of a complex society and economy throughout Germania. Germanic-speaking peoples originally shared similar religious practices. Denoted by the term Germanic paganism, they varied widely throughout the territory occupied by Germanic-speaking peoples. Over the course of Late Antiquity, most continental Germanic peoples and the Anglo-Saxons of Britain converted to Christianity, but the Saxons and Scandinavians converted only much later. Traditionally, the Germanic peoples have been seen as possessing a law dominated by the concepts of feuding and blood compensation. The precise details, nature and origin of what is still normally called "Germanic law" are now controversial. Roman sources state that the Germanic peoples made decisions in a popular assembly (the thing) but that they also had kings and war-leaders. The ancient Germanic-speaking peoples probably shared a common poetic tradition, alliterative verse, and later Germanic peoples also shared legends originating in the Migration Period.
The publishing of Tacitus's Germania by humanist scholars in the 1400s greatly influenced the emerging idea of "Germanic peoples". Later scholars of the Romantic period, such as Jacob and Wilhelm Grimm, developed several theories about the nature of the Germanic peoples that were highly influenced by romantic nationalism. For those scholars, the "Germanic" and modern "German" were identical. Ideas about the early Germans were also highly influential among and were influenced and co-opted by the Nazis, which led in the second half of the 20th century to a backlash against many aspects of earlier scholarship.