The history of Europe from 950-1250 is one of political, territorial, cultural, and economic expansion to a degree hardly conceivably at the beginning of the tenth century. Though broad ranging, this evolution is most easily visible in military-territorial terms. While the Europe of 900 was under siege by Magyars from the Southeast, Arab Muslims from the West and South, and Vikings from seemingly all directions, by 1100 at the latest it was the European polities that were on the move, hemming in or taming their neighbors and opponents. That individual European elites and monarchs could contemplate military campaigns in the Middle East, and then make good on these contemplations, is stark evidence of strides in manpower and motive forces. Of course, this reinvigoration is closely related to political and ideological evolutions distinguishing the post-1000 era from the 700-900s in such a manner that the later period appears to us as a much more mature phenomenon.
In terms of political evolution, all the pre-850 states, with the extremely notable exception of Byzantium, crumpled under the foreign military onslaughts. Unitary sates--in the form of the Carolingian Empire--were unable to maintain stability, and a seemingly irreversible process of feudal localization of political, economic, and judicial power set in. During the first half of the High Middle Ages, though, the picture begins to change. In Germany, Henry the Fowler came to power and was able to begin holding back the Magyars. His descendents, in the form of the Saxon dynasty of Germany, instituted the "Ottonian System," a system of reliance on and control of the clergy, providing a monarchical administration that sidestepped the various duchies' leaders and thereby neatly avoided a full descent into localized feudalism. The nobles revolted throughout the period, but were never, until 1100, as strong as or as wealthy as the Church-reliant monarchy. In France, Hugh Capet and his descendants were forced to take another route, since the feudal localization of power was most advanced there, with counts and dukes allowing the monarchy's continuation only because its occupants were deemed quite weak. The Capetian dynasty gradually became stronger by working within and through the feudal political system. Eventually seen as the highest feudal lord, they used ties of vassalage and notions of feudal legal propriety to build up their power and wealth to the point that St. Louis IX could rule supreme in a French domain much larger even than the domains belonging to the Western Carolingians'. Spain in turn, while not renouncing feudalism in its Christian parts, was also a variation in that to attract settler-warriors for the Reconquista, Spanish sovereigns in Castile, Aragon, and other areas were quite liberal in the exemptions from feudal dues that they gave their subjects. In sections of Italy, the feudal model breaks down further, as urban communes wrested self- control from surrounding petty nobles, then forced the nobles into the cities. The communes continued to resist control from above, even when the opponent was the Pope or Holy Roman Emperor.
Ideologically, too, this period shows an expanding horizon. Building on a foundation of monastic reform begun in the 900-1000s, the Papacy itself began to spearhead a reform of the Church as a whole, targeting clerical marriage and purchasing of prelate positions. Ultimately, the reform logic proceeded to demand that the Pope be the supremely recognized controller of the whole Church through a powerful administration in Rome, and that the Church, in the person of the Pope, have freedom untrammeled by elite laymen in all ecclesiastical matters. The Church began to demand that there be no secular political interference in the form of investiture of bishops or nomination of popes. This policy, of course, brought the Church into continuing conflict with secular kings, the German monarchy in particular. For its part, the German monarchy (as well as other kings) still aspired to that supposedly perfect union of Church and state exhibited by Charlemagne, who controlled his church. On the one hand, this desire exacerbated conflicts on the intellectual and political level, but it would also inspire monarchs to support both Christianization along the margins and campaigns against internal heretics. Whereas on individual matters Church and state often found themselves at odds, the entire intellectual structure of the time culminated in making the Crusades a viable notion in the minds of Church, kings, and feudal lords. This idea grew so powerful, it was able to capture the efforts and attentions of these various groups for centuries, even though the results, with the exception of Spai,n were ultimately so much less than had been hope.
Less obvious, but instrumental to Europe's expansion, was the economic development from the late 900s. This process is visible primarily in town- development in central Europe, as well as in the flowering of commercial city- states in the Italian peninsula. Urban development in northern and Western Europe provided the financial backing for monarchs as well as feudal lords in the form of taxes and customs, and also provided new constituencies in support of further commercial expansion. This development would have great import past 1250, all the way into the seventeenth century. In more immediate terms, this entire period saw the initially plodding, then gradually faster development of Italian coastal cities organized by traders, for trade. Venice was the most conspicuous example of such a city-state, ruled as it was by a commercial oligarchy headed by the Doge. Its foreign policy consisted almost entirely of the effort to open up more areas for trade. To Venice must be added Amalfi, and later Pisa and Genoa. Of course, the Crusades aided in the economic expansion, as Latin warriors, and an impoverished Byzantine state, needed the maritime city states to provide naval forces, transportation, and much-needed commodities. The model that the Italian merchant states set, of establishing trade enclaves throughout the Aegean and Mediterranean that were politically tied to the center, would later be emulated by the Portuguese and Spanish in North and West Africa, hinting at the future Voyages of Discovery.
Also important in this period is the gradual eclipse of Byzantium. From 900- 1261, the Empire rose to heights unknown since the rule of Heraclius in 628 and then fell prey to internal decay and external contraction, falling to its lowest point when it was occupied by Latin knights in the most profound perversion of the Crusades idea. In every respect though--in its bureaucracy, diplomatic skill, theological accomplishments, philosophical speculation, understanding of Islam, and wealth the Byzantine Empire remained far ahead of the West. We must attribute its difficulties during this period to yet another wave of nomadic migrations onto its soil (the Turks) combined with the unwillingness of indigenous elites to look out for anything but their own interests at a time when they no longer had the luxury to do so.
In some ways, all this does not exhibit a protean change from the Europe of the 7-800s, and neither was there a paradigm shift. The relationships between king and feudal lord, church and state, and distrust of the Muslims that animated the High Middle Ages certainly existed in the Medieval era's early years. The Carolingians of the 650s-800s had risen because of personal lord-vassal relations, and saw them as totally legitimate. Similarly, Charles Martel, Pepin, Charlemagne, and Louis the Pious had definite ideas regarding the church-state link, and they all felt they knew best how to protect and mentor Christianity, while taking advantage of its worldly components. In turn, Popes of that era used secular leaders to shore up their positions, and claimed the right to overlordship over them, with just as little sustained success. Finally, part of the era's Christian identity involved anti-Muslim animus, and the military fight against them. Of course, in the High Middle Ages as well as in the early Medieval period, hatred of the other in one's midst--be it heretic, or more often Jew--was a rampant disease.
This points to the inexcusable darker side of medieval life: intolerance was the rule, the policy. With a Christian frame of mind seeing itself as the only correct way, anything else was not simply wrong, but consigned to necessary extermination (as was the case for heretics or excessively speculative philosophers) or to subsistence in abject penury, ignominy, and social disability, as was the case for Jews. With the exception of more tolerant climes such as Muslim and early Christian Spain and Sicily, the intolerant approach was ubiquitous, tempered only by practical concerns such as the financial benefits of squeezing the out-group dry. At times, especially among the almost universally illiterate, uneducated, and superstitious masses, anti- Jewish animus exploded into an orgy of plundering and murder, as in the Peasants' Crusade. In this respect, medieval society from the 400s through the 1500s progressed not at all.