Further north the yellow races were less successful. Along the shifting
borderlands of Asia which mark the line of demarcation between the two
mightier families of man, the tide turned ever more steadily in the
Aryans' favor. The Russians, under their chief, Ivan III, threw off the
galling Tartar yoke which they had borne for over two hundred years.
Ivan concentrated in his own hands the power of all the little Russian
duchies, overthrew the celebrated Russian republic of Novgorod the Great,
and defied the Tartars. Equally noteworthy to modern eyes was his wedding
with Sophia, heiress of the last of the emperors of the East. When that
outworn empire perished with the fall of Constantinople, Ivan succeeded
nominally at least to its heirship. Hence it is that his successors have
assumed the title of caesar or kaiser or czar and have grown to look upon
themselves as inheritors of the ancient supremacy of Rome.[6]

The fifteenth century was thus a time of many changes in Eastern Europe.
Not only did the Eastern Empire disappear at last, not only did Hungary
rise to the brief zenith of her glory, there was a sort of general
movement, sometimes spoken of as the "Slavonic reaction," against the
hitherto successful Teutons. The Slavic Bohemians in their "Hussite" wars
repelled all the religious fighting strength of Europe. The Poles began
to win back territory from the German empire, and especially from their
hereditary foes the "Teutonic Knights" of Prussia. And Russia, greatest
of all the Slav countries, grew into a strong kingdom. She and Turkey,
rising as twin menaces to the West, assumed at almost the same period
that threatening aspect which Turkey has only lately lost, and Russia, to
some statesmen's eyes, still holds.

POLITICAL CHANGES IN WESTERN EUROPE

Turn now to the affairs of Western Europe. The feebleness of the German