In the twelfth century, then, we find in the full flush of life a number of prosperous Italian republics or "communes," closely resembling in many respects the City-States of ancient Greece. The salient differences were (1) the Christian Church, with its wealth[541] and its elaborate organisation; (2) the pretensions of the Empire; and (3) the presence of feudal nobles, some of whom were first imposed by the German emperors on the cities, and who, after their exodus and their life as castle-holders, had in nearly every case compromised with the citizens, spending some months of every year in their town palaces by stipulation of the citizens themselves. All of these differentia counted for the worse to Italy, in comparison with Hellas, as aggravations of the uncured evil of internal strife. The source of their strength--separateness and the need to struggle--was at the same time the source of their bane; for at no time do we find the Italian republics contemplating durable peace even as an ideal, or regarding political union as aught save a temporary expedient of the state of war. On the familiar assumption of "race character" we should accordingly proceed to decide that the Italians, by getting mixed with the Teutons, had lost the "instinct of union" which built up Rome. Those who credit "Teutonic blood" with the revival never think of saddling it with the later ruinous strifes of cities and parties, or with the vices of the "Italian character." The rational explanation is, of course, that there was now neither a sufficient preponderance of strength in any one State to admit of its unifying Italy by conquest, nor such a concurrence of conditions as could enable any State to become thus preponderant; while on the other hand the Empire and the Church, each fighting for its own hand, were perpetual fountains of discord. The factions of Guelph (papal) and Ghibelline[542] (imperial) stereotyped and intensified for centuries every proclivity to strife inherent in the Italian populations.