In the year 1400 the princes of Europe sympathetically were much bestirred, fearing the imminent fall of Constantinople and the extinction of the Eastern Empire. The Ottoman Sultan Bazayid (otherwise Bajazet) was already in possession of almost the whole of what subsequently became Turkey in Europe. The Emperor Manuel still was lord of Constantinople, but beyond the city walls possessed a mere strip of territory along the north coast of the Sea of Marmora, and extending to the Black Sea, a strip some fifty miles in length but under thirty in breadth. Four years before (September 1396) an...