Otto I summary

Emperor, title designating the sovereign of an empire, conferred originally on rulers of the ancient Roman Empire and on various later European rulers, though the term is also applied descriptively to some non-European monarchs. In republican Rome (c. 509–27 bce), imperator denoted a victorious

Church and state, the concept, largely Christian, that the religious and political powers in society are clearly distinct, though both claim the people’s loyalty. A brief treatment of church and state follows. For full treatment of the separation of religion and politics, see secularism. For full

War, in the popular sense, a conflict between political groups involving hostilities of considerable duration and magnitude. In the usage of social science, certain qualifications are added. Sociologists usually apply the term to such conflicts only if they are initiated and conducted in accordance

Holy Roman Empire, the varying complex of lands in western and central Europe ruled by the Holy Roman emperor, a title held first by Frankish and then by German kings for 10 centuries. The Holy Roman Empire existed from 800 to 1806. For histories of the territories governed at various times by the