how any extended trade could be carried
on without some unit of value, yet no coins are known earlier than the
Iron Age.<12> The most ancient coins known are Greek, and date back to
the eighth century before Christ. This coin is one found in one of the
lake settlements. It is made of bronze, and the figures are not stamped,
but obtained by melting and casting.<13> This, however, is not a Greek
coin, but a Gallic one. On the battlefield of Tiefenau, mentioned above,
several Greek coins, struck at Massilia, were found.<14>

It is scarcely necessary to point out, that though iron gives its name
to this age, it by no means follows that the only difference between
this and the Bronze Age is the use of iron. "The pottery is different,
the forms of the implements and weapons are different, the ornamentation
is different, the knowledge of metallurgy was more advanced, silver and
lead were in use, letters had been invented, coins had been struck."<15>
That wonderful invention, the phonetic alphabet, was made during the
early part of this age. The past was no longer simply kept alive in the
memory of the living, handed down by tradition and song. Inscriptions,
and monuments, and books abounded, and we are no longer confined to an
inspection of their handiwork, or examination of their habitations, and
explanation of ancient burial mounds for our knowledge of their life and
surroundings. It is no longer the archaeologists' collections, but the
writings of the historian that unfolds past times and customs.

Let us cast a glance at the condition of Europe at the dawn of history.
We have seen that in general terms the Bronze Age coincided with the
arrival and spread of the Celts, though the earlier Celts were still
Neolithic. The use of iron could scarcely have been inaugurated before
the innumerable hordes of the Germanic tribes, probably driven from
their Asiatic homes by the presence of invading people, were on the
march. The world has, perhaps, never witnessed such a movement of people
as convulsed Europe for several hundred years, beginning the second
century before Christ and continuing until the fall of the Western
Empire of Rome. The light of history dawns on a stormy scene in Europe.
The Celts confined to the Western portion had been largely subjected by
the Roman armies, but the largest portion of Europe held by the Germanic
tribes was the seat from whence assault after assault was made on the
Roman Empire, which at length,