54 THE HISTORY OF MEDIEVAL EUROPE Mithridates, a handsome giant of Persian descent and Greek education, a great athlete and linguist, an able orator and general, but withal a cruel Oriental despot, was pro- tecting the Greek cities of the Black Sea against the north- ern barbarians who threatened them, was building up an empire for himself about the Black Sea, and was spreading Greek civilization through it. In this respect, however, he could make only a beginning, since his empire included all sorts of races, languages, and religions, and peoples in every stage of civilization from tree-dwellers, pile-dwellers, and the pastoral stage up. In a single city of his realm as many as seventy dialects were spoken. _His promising beginning was soon terminated by wars with Rome which resulted in his downfall. Rome annexed some of his possessions on the southern coast of the Black Sea, but let the rest go, and the Greek cities soon succumbed to barbarian pressure. These barbarians were now spoken of as Sarmatians rather than Scythians. About the beginning of the third century a.d. these Sarmatians were for the most part driven out by the Ger- man Goths, who migrated from their earlier home on the Baltic to the Black Sea. The middle of the third century was a period of civil strife and mis- government in the Roman Empire, which came near going to pieces as a result. The Goths took advantage of this state of affairs to cross the Danube and the Balkans, and to defeat and kill the Emperor Decius. They also ravaged the shores of the Black Sea with their fleets, completely devastated the Roman province of Bithynia, and, passing through the Dardanelles into the ^Egean Sea, wrought havoc and ruin along its coasts. Meanwhile, in the West the Franks had crossed the Rhine into Gaul and then into Spain, and other Germans had invaded Italy itself, while Moorish tribes made trouble in northwestern Africa. Finally the barbari- ans were defeated, but the emperors found it necessary to surround the city of Rome by walls once more, and to abandon Dacia, a large province on the north side of the lower Danube which had been added to the Empire at the
