The Holy Roman Empire was an attempt to revive the Western Roman Empire, whose legal and political structure deteriorated during the 5th and 6th centuries, to be replaced by independent kingdoms ruled by Germanic nobles. The Roman imperial office was vacant after the deposition of Romulus Augustulus in 476. During the turbulent early Middle Ages the traditional concept of a temporal realm coextensive with the spiritual realm of the church had been kept alive by the popes in Rome. The Byzantine Empire, which controlled the provinces of the Eastern Roman Empire from its capital, Constantinople (now Istanbul, Turkey), retained nominal sovereignty over the territories formerly controlled by the Western Empire, and many of the Germanic tribes that had seized these territories formally recognized the Byzantine emperor as overlord. Partly because of this and also for other reasons, including dependence on Byzantine protection against the Lombards, the popes also recognized the sovereignty of the Eastern Empire for an extended period after the enforced abdication of Romulus Augustulus.

Growing Tensions

With the coalescence of the Germanic tribes into independent Christian kingdoms during the 6th and 7th centuries, the political authority of the Byzantine emperors became practically nonexistent in the West. The spiritual influence of the western division of the church expanded simultaneously, in particular during the pontificate (590-604) of Gregory I. As the political prestige of the Byzantine Empire declined, the papacy grew increasingly resentful of interference by secular and ecclesiastical authorities at Constantinople in the affairs and practices of the Western church. The consequent feud between the two divisions of the church attained critical proportions during the reign (717-41) of the Byzantine emperor Leo III, who sought to abolish the use of images in Christian ceremonies. Papal resistance to Leo's decrees culminated (730-32) in a rupture with Constantinople. After severance of its ties with the Byzantine Empire, the papacy nourished dreams of a revivified Western Empire. Some of the popes weighed the possibility of launching such an enterprise and assuming the leadership of the projected state. Lacking any military force or practical administration, and in great danger from hostile Lombards in Italy, the church hierarchy, abandoning the idea of a joint spiritual and temporal realm, seemed to have decided to confer imperial status on the then dominant western European power, the kingdom of the Franks. Several of the Frankish rulers had already demonstrated their fidelity to the church, and Charlemagne, who ascended the Frankish throne in 768, had displayed ample qualifications for the exalted office, notably by the conquest of Lombardy in 773 and by the expansion of his dominions to imperial proportions.

The Western Empire

On December 25, 800, Pope Leo III crowned Charlemagne emperor. This act established both a precedent and a political structure that were destined to figure decisively in the affairs of central Europe. The precedent established the papal claim to the right to select, crown, and even depose emperors that was asserted, at least in theory, for nearly 700 years. In its primary stage, the resurrected Western Empire endured as an effective political entity for less than 25 years after the death of Charlemagne in 814. The reign of his son and successor, Louis I, was marked by feudal and fratricidal strife that climaxed in 843 in partition of the empire. For an account of the growth, vicissitudes, and final dissolution of the Frankish realm, see FRANCE. Despite the dissension within the newly created Western Empire, the popes maintained the imperial organization and the imperial title, mainly within the Carolingian dynasty, for most of the 9th century. The emperors exercised little authority beyond the confines of their dominions, however. After the reign (905-24) of Berengar I of Friuli, also styled as king of Italy or ruler of Lombardy, who was crowned emperor by Pope John X, the imperial throne remained vacant for nearly four decades. The East Frankish kingdom, or Germany, capably led by Henry I and Otto I, emerged as the strongest power in Europe during this period. Besides being a capable and ambitious sovereign, Otto I was an ardent friend of the Roman Catholic church, as revealed by his appointment of clerics to high office, by his missionary activities east of the Elbe River, and finally by his military campaigns, at the behest of Pope John XII, against Berengar II, king of Italy. In 962, in recognition of Otto's services, John XII awarded him the imperial crown and title.

A Union of Germanic States

The empire in the West, at first an unstable union of Germany and northern Italy and later a loose union of Germanic states, remained in almost continuous existence for more than 800 years. During the Italo-German phase, the empire played a significant role in central European politics and ecclesiastical affairs. A central feature of this period was the mortal struggle between the popes (notably Gregory VII) and the emperors (notably Henry IV) for control of the church. With the Concordat of Worms (1122), an agreement between Emperor Henry V and Pope Callistus II, the emperor relinquished the right of spiritual investiture, or installation of bishops into ecclesiastical office. All the emperors were German kings, and because imperial duties and ambitions inevitably required their full attention, local German interests were neglected. As a result, Germany, which might have been transformed into a strong centralized state, degenerated into a multiplicity of minor states under aristocratic rule. The agreement at Worms had removed one source of friction between church and state, but through the 12th century the struggle for political ascendancy continued. In 1157 Frederick I, called Frederick Barbarossa, one of the greatest of emperors, first used the designation Holy Empire, ostensibly to increase the sanctity of the Crown. Frederick, attempting to restore and perpetuate the ancient Roman Empire, tried to suppress both the restless nobles of Germany and the self-governing cities of Italy. His interventions in the latter country were opposed by the Lombard League and severely strained his relations with the papacy. Pope Adrian IV insisted that Frederick held the empire as a papal fief, but the emperor, who had the support of the German bishops, maintained that his title to it came from God alone. During the almost two decades of sporadic warfare in Italy that followed, Frederick was defeated at Legnano (1176) by the cities of the Lombard League, and the cities thus established their independence from further imperial authority. Emperor Henry VI, who claimed the throne of Sicily through marriage, twice invaded Italy and the second time (1194) made Sicily his in fact. Emperor Frederick II renewed imperial efforts to vanquish the Italian cities and the papacy in the 13th century, but he was unsuccessful.

The Holy Roman Empire had little real importance in European political and religious developments after the Great Interregnum (1254-73). The death of Frederick II in 1250 left the imperial throne vacant, and two rival candidates attempted to win support for their claims. Frederick's son, Conrad IV, and William of Holland first contended for the throne. In 1257 another imperial election was followed by the crowning at Aachen of the English Richard, earl of Cornwall, who was, however, unable to win control of the empire. In effect, this signalized papal victory in the protracted struggle with the empire. Beginning in 1273 with Rudolf I, the first of the Habsburg dynasty, various German kings laid claim to the imperial title and, in several instances, these claims were recognized by the popes. The office was little more than honorary, however, and inasmuch as the empire comprised a loose confederation of sovereign states and principalities, imperial authority was nominal. Louis IV, who assumed the title in 1314, successfully challenged the power of the papacy and for a brief period restored the prestige of the empire. In 1356 Charles IV promulgated the Golden Bull, which prescribed the form and procedure of imperial election and enhanced the importance of the electors. During the reign of Charles V, the empire encompassed territories as extensive as those of Charlemagne; but dynastic rather than ecclesiastical principles composed the chief cohesive element in the imperial structure of Charles V. The medieval concept of a temporal state coextensive and in harmony with the spiritual dominions of the church survived solely as a theory. As the Protestant Reformation gained headway, even the theory lost practical meaning. The unity of the empire was weakened in 1555 after the Religious Peace of Augsburg permitted each free city and state of Germany to exercise choice between the adoption of Lutheranism or Catholicism. With the Peace of Westphalia in 1648, which ended the Thirty Years' War, the empire lost all remaining sovereignty over its constituent states and France became the leading power in Europe. In its final phase the Holy Roman Empire served mainly as a vehicle for the imperial pretensions of the Habsburgs, but it performed certain useful functions, including the maintenance of a measure of unity among its component states. The later emperors, all rulers of Austria and concerned mainly with aggrandizement of their personal dominions, were mere figureheads. Futile armed intervention against the French Revolution constituted the last important venture of the empire in European politics. Because of well-founded fears that Napoleon I of France intended to annex the imperial title, Francis II, the last of the emperors, formally dissolved the empire on August 6, 1806, and established the Empire of Austria.