Christianity in the High Middle Ages
This chapter describes trends in the practices, doctrines, and institutions of Catholic Christianity. The late eleventh, twelfth, and thirteenth centuries are often called the High Middle Ages in order to distinguish them from the prior period and from the one that followed, which led up to the Protestant Reformation. These centuries are also “high” in the sense that they mark numerous peak developments and events of lasting importance in the Christian tradition. Modern historians have given the name of Christendom to this unprecedented merging of Christianity and culture. By the end of the eleventh century, almost all of Europe had become nominally Christian. Jewish and Christian scholars and theologians, for example, made constructive contacts over the study of the Bible. Medieval Christianity’s relations with Islam are characterized most famously by the Crusades, the Christian holy wars that, beginning in the late eleventh century, the medieval church launched against unbelievers, especially Muslims, and heretics.
The Christian Theological Tradition, 4th ed.