CHAPTER III . THE BARBARIAN WORLD OUTSIDE THE EMPIRE One thinks of the Roman Empire as including the whole ancient civilized world, except distant China and India. Limits of ^ ut ^ should be remembered that, if the Romans the Roman had spread Greek culture to Western lands like Empire Gaul and g^taiii, they had lost a large part of the empire of Alexander the Great, and that their frontier went no farther east than the Euphrates River and the Arabian Desert. They were unable to conquer and hold the Tigris- Euphrates Valley, once the most civilized and influ- ential region on earth. Here they were successfully opposed, first, by the Parthian, and then, after 227 a.d., by the Per- sian Kingdom. Of the vast continent of Africa they occu- pied only the Nile Valley and the Mediterranean coast. The greater part of the area and many of the nations of modern Europe lie outside the Roman boundary. It did not include Russia, Denmark, Norway, Sweden, Ireland; it included only a little of Scotland, the Netherlands, and the German Empire; and not all of Austria-Hungary. In these lands, as well as in the East, lived peoples whom Rome had failed to subdue, and who were destined some day to subdue her. By 117 a.d. she had reached the limit of her conquests; the question then became how long would she hold what she had? In distant Britain she had to build walls across the island to keep out the Picts and other barbarians of the northern highlands, while Celtic Ireland was left uncon- quered under the rule of the chiefs of many clans. Around the Baltic Sea and to the east of it dwelt Scandinavian and Finnish and Slavic tribes of whom the Romans knew next to nothing, and who were not to appear in history for some time to come. Nearer to the Roman frontier were the " German barbarians," extending from the North to the Black Sea, They were to deal the death-blow to ancient Rome,
