The Celtic and Roman Iron Ages: 500 B.C.E. - 350 C.E.
The use of iron came to Northern Europe around 500 B.C.E. The period from 500 B.C.E. - 0 C.E. is called the Celtic Iron Age because the Celts dominated most of Europe at this time, while the Germanic peoples were largely limited to the Scandinavian area. Although linguistic evolution is difficult to date due to a total lack of any direct evidence, the accepted hypothesis dates the First Sound-Shift (Grimm's Law) which distinguishes Germanic from other Indo-European languages, to roughly 500 B.C.E., so that it is probable that the Scandinavians were speaking Proto-Germanic at this time.
Compared to the riches of the Bronze Age, the Celtic Iron Age was a relatively poor time for the Germanic peoples. The climate in Scandinavia was growing colder and wetter, forcing farming practises and the general lifestyle to change. Cattle had to be kept inside in the wintertime, usually sharing a long house with their owners; the living practices of the Northern folks in this period were probably unhealthier than they had ever been. However, improved ploughing techniques which made it possible to till the heavy clay soil also made it possible for fields to be used much longer before their fertility was exhausted, making settlements more stable in the long run and perhaps leading to a greater degree of social development and cultural continuity. No longer maintaining the widespread trade network which had brought them bronze, the Northerners were probably dependent on the Celts for iron; the Germanic word is thought to have been borrowed from the Proto-Celtic *isarno. In the early part of this period, the Celts clearly held a position of social dominance as well, as the Germanic word for ruler, *rikaz (German Reich/English "rich"/Old Norse ríkr, "powerful") was also borrowed from the Celtic (Schutz, Prehistory of Germanic Europe, pp. 312-13). The social stratification which had become noticeable in the Bronze Age became much clearer in the Iron Age: the institution of the warband, which was to give the heroic tales of the Migration and Viking Ages their shape, probably grew up around this time, perhaps formed after Celtic models.
The Germanic people were clearly not subjugated by the Celts, however; fine Celtic-made goods often found their way north along the trading paths. The most spectacular of these pieces is the huge silver Gundestrup Cauldron, which was probably made by Central European Celts around 100 C.E., but was put in a Danish bog as a sacrificial offering.
The Germanic peoples began to push southward onto the Continent roughly around 200 C.E. It may have been about this time that the East Germanic branch (Goths, Burgundians, and several lesser tribes) began their migration into the steppes of Eastern Europe. It is also at this time that we can begin to consider with any certainty that the Germanic peoples knew their god/esses by the Proto-Germanic forms which evolved into the familiar Anglicized-Norse Odin, Frigga, Thor, and so forth. The Gothic alphabet preserves the names "Engus" (*Ingwaz - Fro Ing or Freyr) and "Tius" (*Tiwaz - Tiw or Týr); it seems likely that the Germanic folk also knew *Woðanaz (Óðinn), *Frijjo (Frigg), and *Thonaraz (Þórr), as well as the personified Sun-goddess (and probably a corresponding Moon-god). Tacitus, writing in the first century C.E., mentions a "Mother Earth" by the name of Nerthus (which developed into the Old Norse god-name Njörðr - see "Nerthus/Njörðr"). As has been pointed out by H.M. Chadwick in his ground-breaking study, The Cult of Othin, the Roman and Greek accounts of Germanic religion at this time and in the few centuries following are remarkably similar to the Old Norse descriptions. It is, therefore, likely that the basic form of the religion as we know it today from the Norse sources was solidified in the first part of the Iron Age, though many of the elements seem to have been present in the Stone and Bronze Ages as well.
Sacrifices of goods continued to be made in bogs and lakes throughout the whole of the Iron Age. With the increased scale of warfare, it became more and more common for the victorious warband to dedicate their foes to the gods. Captured weapons were bent, burnt, or broken, horses killed, battle-captives slain, and some or all of the booty tossed into a body of water. The oldest large sacrifice of this sort is the Hjortspring find (4th century B.C.E.), which included 169 spear-points, 11 swords, remains from several byrnies, and a large war-boat. A similar, though much larger, deposit was made at Illerup around 200 C.E.; smaller finds of this sort are relatively common through the sixth century C.E. The chief receiver of sacrifices of this type, as described in The Cult of Othin, was probably *Woðanaz; *Tiwaz has also been suggested, as he was once the "Sky-Father" of the Teutonic folk and later identified with "Mars" when the weekday-names were translated into Germanic, but there is little solid evidence for this.
Human sacrifice in the bogs also became relatively common during this period; the peat and anaerobic environment preserved these bodies so that not only the corpses and their clothes and gear stayed whole, but even the contents of the stomach can sometimes be analyzed. The most famous of these "bog people" is the Danish Tollund Man. A relatively young man, probably of high social status (his hands showed no signs of manual labour, which is true for an unusual number of bog people), he had been fed a porridge of late-winter gruel including a number of wild grains, then hanged and put into the bog clad only in skin cap, belt, and noose. P.V. Gløb theorizes that Tollund Man was a sacrifice to the goddess Nerthus, suggesting that the gruel of blended wild and cultivated grains may have been a symbolic mixture to encourage the goddess' spring return. He also compares the rope nooses which several bog-people wear to the twisted neck-rings of the goddess, "the pass which carries (the bog man) over the threshold of death and delivers him into the possession of the goddess, consecrating him to her for all time" (The Bog People, pp. 165-166). It is also possible, however, that this hanged man may have been given to Wodan: there are ten or twelve places in Sweden called "Óðinn's lake", and a South Jutlandic "Óðinn's bog" (de Vries, Altgermanische Religionsgeschichte II, pp. 50-51).
In addition to the sacrifices themselves, many god-images survive from the Germanic marshlands throughout the whole of the Iron Age. Perhaps the best-known of these is the "Nerthus" from Foerlev Nymølle, a 9-foot forked oak branch with a shape naturally resembling a tall, slender female form and carving done at the crotch of the fork to make the identification perfectly clear. She was laid in a cairn of stones with a heap of pots around her; Schutz suggests that this may have been "her abode, to which she retired between festivals" (The Prehistory of Germanic Europe, p. 332). Both distinctively female figures, such as "Nerthus" and the smaller, but equally explicit figure from Rebild Skovhuse, and definitely male figures, such as the phallic god from Broddenbjerg (also found among a heap of stones in a bog with pottery around him) appear; on the Continent, male-female pairs are also found, such as the two from Braak (southern Jutland) and the bridge-guardians from the Oldenburg moors. Schutz comments that, "In spite of (the Germanic peoples') sophisticated tools and skill as craftsmen, the awkward crudeness of all these figures is striking and must have been deliberate" (The Prehistory of Germanic Europe, p. 333).
At this time, we also have our first record of holy groves. Although it is likely that the Germanic folk had been worshipping in groves and on top of mountains, as well as by lakes and bogs, for a long time, only the wetlands preserved the gifts to the gods which would have long since have rotted or rusted away in open air. Thus, it is only through Tacitus' report in Germania ch. 9 that the Germans "consecrate groves and coppices" and his descriptions of the holy grove of the Semnones (Germania ch. 39) and the grove where the booty from the Battle of Teutoberger Wald was hung (Annals I, ch. 61), that we know that the Germans of the early Iron Age were worshipping in much the same manner as did the Norse of the Viking Age.
By the beginning of the Common Era, the Germanic people had settled throughout most of modern Germany. Tacitus tells us that the many tribes were divided into three larger groups, the "Ingvaeones" nearest the North Sea (Jutland/North Germany), the "Hermiones" in the middle part of the country, and the "Istavaeones" everywhere else. The Germanic expansion was stopped in the first century B.C.E. by the counter-expansion of the Roman Empire, which had already devoured Gaul and was now reaching over the Rhine. Rome's attempt to subjugate and acculturalize the folk of "Germania" came to an end in 9 C.E., when Hermann the Cheruscan (called "Arminius" in the Latin sources) entrapped and destroyed three Roman legions at the Battle of Teutoberger Wald. After that battle, the Rhine remained the frontier between the two folks until the Germanic tribes began to cross it in the Migration Age.
Although the Germanic peoples were never conquered by the Romans, it was common from a very early date for Germanic men to serve in the legions; Hermann, in fact, had been one of those soldiers, and learned the strategy and organization which made the victory at Teutoberger Wald possible in the Roman army. Roman goods, such as glass vessels and swords inlaid with gold figures of Mars, also made their way north to Denmark. As was characteristic of Imperial practise, the Romans along the border of the Rhine integrated local belief with their own, so that a great many votive stones with Latin inscriptions actually refer to Teutonic deities. Our knowledge of the Continental cult of the Mothers (matronae - see "Idises"), for instance, comes to us solely through such Romano-Germanic votives. Much of our knowledge of early Germanic religion is through such altars and the writings of Roman historians. However, the tendency of Romans to not only translate the names of foreign deities into those of their own (the interpretatio Romana), but to do it indiscriminately and haphazardly, as with the unarmed and cornucopia-bearing "Mars Ollodius" (Great Tree) from Custom Scrubs, Britain (Miranda Green, Gods of the Celts, p.118-19), sometimes makes it a problem to determine which native god was meant. Mars and Mercury are the most difficult names to evaluate, since they were the two most popular and, in the Celtic area, seem to have been used interchangeably (F. Benoit, Mars et Mercure). The other source evidence, however, suggests that most of the time, *Woðanaz was probably the god meant by "Mercurius"; whether "Mars" sometimes referred to this god as well is still open for question.
The fluid character of the interpretatio Romana was not solidified until the late third or early fourth century. At that time, the Romans had acquired the seven-day week from the Middle East and set the names of their own gods to it: Sun-day, Moon-day, Mars'-day, Mercury's-day, Jupiter's-day, Venus'-day, and Saturn's-day. When the interpretatio Germanica was applied to the weekdays, it resulted in a fairly standard Sun-Day, Moon-Day, Tiw's-day, Wodan's-day, Thonar's-day, and Frija's-day ("Saturn" never had a standard translation, perhaps because Wodan had already been used for Mercury and the other Germanic deity of death was a goddess - Hella - rather than a god). Thereafter, with a few antiquarian exceptions identifying Wodan with Mars because of his role as a battle-god, the Germanic identities of "Mercury", "Mars", "Jupiter", and "Venus" were firmly established.
Even though the weekday-attributions were not originally Germanic, we have been calling them by the names of our god/esses (and hence, knowing or not, calling on those god/esses) for some seventeen hundred years. Thus the choice of weekdays in worshipping individual deities is a matter of some worth: as Wodan has been called most often on Wednesdays, or Frija on Fridays, they are likely to be stronger on the days given to them.
For the three hundred fifty years of the Roman Iron Age, major changes were taking place within Germania. Northern tribes were continuously moving southward, partially in search of better land and partially because the migration from Scandinavia was apparently continuing. The East Germanic tribes in Eastern Europe, under great pressure from the migrating horde of the Huns, were also moving westward into Germania at this time. In the process of these movements, the smaller tribes that Tacitus had described were gathering into larger and more powerful groupings such as the Alamanns ("all the folk") and the Franks. In 166, the tide of Roman expansion/invasion was abruptly reversed: the Quadi and Marcomanni broke the Roman borders in Venetia, and the Costobocci and the Bastarnae in Achaea and Asia. The Romans quickly regrouped and closed the frontier again, but not easily. In the middle of the third century C.E., several breakthroughs took place: Belgium, Upper Germany, Italy and Greece were all invaded and Gaul very seriously ravaged by various Germanic folks. Eventually the Romans managed to restore their old borders, except for Dacia, which was left to the Goths. Musset comments that, "In the end the brutal energy of Diocletian succeeded, after a generation of disasters, in keeping the Germans out of the Empire. But they had weighed up both its wealth and its weakness, and were not likely to forget either" (The Germanic Invasions, p. 11).