A change in the climate of northern Europe at the beginning of the Iron Age had led to a series of migrations by Germanic-speaking peoples in Scandinavia into what is now northern and central Germany. The nature of farming and settlement in this new region meant that these movements were gradual, with families, bands and clans expanding into uninhabited or lightly inhabited regions around them and establishing scattered, independent settlements.

Occasionally conflict or agricultural conditions sparked larger-scale migrations or invasions and annexations of neighboring territories. A combination of these two types of expansion meant that, by 272 BC, federations of clans with common ancestral ties began to form into loosely structured tribes and these newer, larger groupings began to expand further toward the Rhine and Danube and raid further afield. Trade, raiding and other contacts made them more aware of their Celtic neighbors and of the Roman world beyond.

In 272 BC the Sêmnonoz, the Márkámánnoz, the Lángobárdoz and the Hêrmunduroz formed the core of a grouping of tribes and bands called the Swêboz - peoples that believed they shared a common heritage from their ancient, legendary ancestor Irminaz. To their west and south-west were other tribal groupings, the Hêruskoz, the Hábukoz and the Háttoz that were growing stronger on the back of richer farmlands and raiding over the Rhine. To the north lay the old homeland of Skándzá, which still saw periodic movements over the Baltic Sea into the forested lands to the east and south-east of the Sweboz . It was a time of opportunity for aggressive warriors and danger for those less able to fend off rivals.

Expansion also led to cultural changes. Population levels rose as the various tribes moved into warmer, richer lands south, west and east. Closer contact with Celtic peoples led to development in metals technology - aided by large iron deposits in upper Poland - which led to better weaponry. Raiding and the aggressive annexation of rivals’ territory also led to the rise of a warrior elite, with warfare becoming a major preoccupation of the tribal leaders and the warrior retinues they began to attract.

The old, looser tribal affiliations gave way to closer ties between clans and bands and changes in the relationships between rulers and the common people. While less socially stratified than Celtic societies, the new warrior elites became an increasingly powerful force within the tribes. The older style of ruler – a semi-sacred/religious leader chosen on the basis of his ancestry – now increasingly shared power with successful war-leaders. Thus the semi-religious Kuningáz and the Eriloz, or clan-leaders and nobles who supported him, would turn to a Hárjánáz elected to lead the tribal warbands in times of war. Sometimes the Hárjánáz was subordinate to the Kuningáz. Sometimes the one man held both offices. Often rival Hárjánoz battled for supremacy in internal feuds and wars.

All free men still held high status in the tribe and no Kuningáz or war-leader could enforce a decision without the support and acclaimation of the tribal assembly of free men. So while Germanic society was changing, it remained suspicious of absolute authority and the Germanic people prided themselves on their independence, freedom and self-sufficiency.

Gift-giving, feasting and the ancient rules of hospitality forged links between families and clans and helped order the relationships between tribes. Feuds and blood vengeance were common, but blood-prices (paid in cattle) were used to settle these outbreaks of violence. A common religious tradition and a shared cultural heritage was one thing all these tribes had in common, and songs of their ancestors in ancient Skándzá and the old gods of distant times were shared by all the tribes. Different tribes held different gods in high regard and had their own local deities and spirits, but all offered cattle and weapons to the gods in sacred places – usually forest groves or swamps. Human sacrifice was common in times of famine or as a thanks offering for victory in war.

In 272 BC these tribes, with their traditions, gods, songs and a dynamic and expanding culture was becoming a threat to the peoples to their south and west. The Gauls already knew of the danger of these people beyond the Rhine but it was not long before the Romans too became aware of the movements – often sudden, violent and massive – of these restless people. This was to lead, in the First Centuries BC and AD, to a long series of wars between the Romans and the Germanic tribes and, many centuries later, to Germanics establishing kingdoms in the ruins of the former Roman Empire.

With the Roman conquest of Illyria, Gaul and, finally, Dacia the Germanic peoples came into constant, direct contact with the Empire along its Rhine and Danube frontiers. This led to several centuries of interaction, cultural exchange, warfare and trade; with a lasting effect on both cultures.

The martial aspects of these confrontations and interactions led to an acceleration of the changes in Germanic society, with war-leaders and their retinues steadily increasing in power and influence within Germania at the expense of older forms of political power. Military confrontation changed the ways Germanic warbands fought, with greater discipline, the use of formations and following standards on the battlefield appearing as early as the opening of the First Century AD. Germanic warriors served in the Roman army as auxilia and mercenaries throughout this period, bring their training, knowledge and, often, equipment back to their native lands on discharge.

Trade also revolutionised the previously impoverished Germanic lands. With amber prized by Roman ladies, the long trade route from the lower Danube up to the Baltic became a source of wealth for the tribes that lay along its path. Raiding into the Empire brought plunder and the Roman practice of playing some chiefs off against each other also led to large payments of tribute and rich gifts, all of which led to coinage circulating in Germanic lands and chiefs and war leaders accumulating wealth which, in turn, attracted warriors, followers and power.

All of these changes gave rise to a slow evolution within the tribes, whereby larger groups absorbed smaller ones, while others formed alliances and federations to protect themselves in an increasingly warlike environment. By the Fourth Century the older, smaller tribes and bands of 600 years before had vanished, replaced by larger tribes or federations of tribes that shared a cultural identity. It was these newer, larger, more militaristic and more powerful tribes that confronted Rome as the western half of the Empire began to decline economically and disintergrate politically in the Fifth Century AD.

At the same time, the Germanic peoples – halted by Rome to the west and south – continued to expand eastwards. By the Third Century Germanic bands were moving out onto the steppes of the Ukraine and mingling with as well as fighting against the Indo-Iranian Sarmatians and Alans they found there. These people also had a profound impact on the eastern Germanic tribes. Some of them, such as the Quadi, Goths, Gepids and Taifali, adopted the heavy lancer cavalry of the Sarmatian peoples, becoming feared heavy cavalry in the process. The Sarmatians also influenced Germanic art, introducing the interlace styles and abstract animal motifs that were to dominate Germanic art for the next 1000 years.

The aggression, restlessness and warlike nature of these tribes that the Romans noted in their first interactions with them remained their hallmarks for the rest of their history, until, by the beginning of the Fifth Century, circumstances and aggressive warfare led to Germanic kings who traced their ancestry to semi-mythic ancestors in the old Germanic homeland of Scandinavia sat on thrones in Italy, Gaul, Spain and Africa.