The line from Szczeczin to Trieste, which Churchill dubbed 'an iron curtain' coincides roughly with the eastern limits of the Carolingian empire of the ninth century as well as with the western border of that region which was dominated by privileged landlords and enserfed peasants from the seventeenth to the nineteenth centuries. But during the central Middle Ages the kingdoms of Poland, Bohemia, and Hungary, and the state of the Teutonic Order -- the polities that dominated the region between Germany and Russia -- were very much part of Europa, or, as learned contemporaries called it, Latin Christendom. The three kingdoms, founded around the year 1000 in an age that had envisaged a renewed Christian Empire, became in the next three centuries constitutive elements of Europe. By the late thirteenth century east-central Europe came to be rather similar to the older centres of Christian-feudal civilization.
During those two centuries that concern us here, this region was not merely a part of Europe, but had acquired an almost central position. By 1400 people beheld the crown of the waning Holy Roman Empire on the head of kings of Bohemia or Hungary, and the intellectual debates were more vivid and seminal at the university of Prague than in Paris or Bologna. It was in this region that such 'international' dynasties as Luxembourg, Anjou and Habsburg attemped to build bases for imperial plans after the old families of Ottonians, Hohenstauffen and Welf had vanished from the scene.
Moreover, east-central Europe was the 'last frontier' both for continental expansion of the West into the eastern plains and also for the defence of Europe from the emerging force of the Ottoman Empire. Such medieval ideals as European-Christian solidarity and 'Latin Christendom' remained here politically forceful notions in contrast to western Europe, where the realities of cultural and economic homogeneity were becoming much more significant in delineating borders, loyalties, and political action. Of course, the states of the area were by the fourteenth century 'multi-national' with different Slavic peoples as well as Germans, Magyars, and Romanians, both Catholics and Orthodox Christians living within the borders of nearly all of them. The notion of crusade and the alternative idea of a European peace organization found considerable sympathy among the people east of the Rhine, while it was hardly taken seriously west of it. The threat of the Turk occupied the minds of many Europeans in the late fifteenth century, especially after the fall of Constantinople, but the brunt of the struggle, rarely aided by more than token participation, was carried by the kingdoms of east-central Europe, which, not without reason, regarded themselves as 'the bulwark of Christendom'.