He allowed the clergy to override him and did humiliating penance for alleged faults; he quarreled with his sons about their rights to the succession and became involved in civil war, which kept up after his death and only ended with the treaty of Verdun, in 843. (See PEACE TREATIES). This treaty divided civilized Europe into three parts, one nearly corresponding to modern France, another to modern Germany and the third being a strip between the other two, extending from the North Sea far down into Italy. After the death of Lothair and of one of the latter's sons this middle strip (Al sace-Lorraine) was divided between Germany and France (Treaty of Mersen (q.v.) 870), but remained a bone of contention down to our own day. Lothair's other son retained Italy.
From 885 to 888 the dominions of Charles the Great were reunited under his great grand son, Charles the Fat. Unable to cope with the invading Norsemen Charles the Fat was de posed and five independent kingdoms arose: Germany, France, Italy, Upper and Lower Bur gundy. Germany itself narrowly escaped fur ther subdivision, but the danger was averted by the election of Conrad of Franconia, chosen possibly because he was related to the Caro lingian house. So slight was the political co hesion that Conrad went to war with the heads of each of the great duchies in turn—Lorraine, Saxony, Swabia and Bavaria—and that he felt compelled on his deathbed to urge the election of Henry of Saxony simply because that prince had been the most powerful of his opponents and could, it was hoped, hold the discordant elements together. It was a good choice. Henry proved a great organizer, training an army, building fortresses and overcoming the wild Hungarians and other Slavic tribes. He left Germany so consolidated that, at the coronation of his son and successor, Otto I, the heads of the duchies — Lorraine, Franconia, Swabia and Bavaria— did feudal, almost menial, service as cup-bearer, steward, chamberlain and marshal. Later, indeed, Otto had to put down rebellions on the part of all these dukes, and he came to rely on the ecclesiastical princes as the stanch est supporters of his throne. He inaugurated the policy, which proved unfortunate in the end, of endowing the clergy with great landed pos sessions. The benefit to him was that at every vacancy, as bishops had no lawful descend ants, these lands reverted to the crown and could again be used to reward faithful service.
Grants made' to the nobles, on the contrary, came to be looked upon as hereditary family possessions, which, being let out in return for feudal service, assured the owners of large bands of faithful retainers. These local powers, especially the great dukes, were very often arrayed against the Crown.
Otto kept not merely the German, but also the Roman, Church in subjection. Drawn into Italian affairs by an appeal from the heiress to that kingdom, he put her enemies to flight, mar ried the heiress, Adelaide, and himself assumed the titles of 4( King of the Lombards" and °King of the Italians.° He restored the empire of Charlemagne with the title of °Holy Roman Empire of the German Nation,* and, for mis conduct, deposed the very Pope (John XII) who had crowned him emperor. Unfortunately these Italian interests drew Otto's successors away from their duties as German rulers. Again and again, with German armies, they de• scended upon Italy; each felt it a vital neces sity to be crowned with the imperial crown at Rome. One consequence of their repeated absences was the loss of the supremacy over the Slavic nations on the German borders.
Otto's ecclesiastical policy was imitated by his son and grandson and led to a gigantic con. flict with the papacy. It was a question ulti mately as to who should control the elections of the German bishops. If the Pope, then he had simply to adjudge the rich German sees to his partisans; the emperor lost the supporters of his throne and the lands might practically as well have belonged outright to Rome. It seemed a life and death struggle, which accounts for its long continuance and for the venom displayed on both sides. There were wonderfully dra matic moments, like the penance at Canossa of Henry IV (1077), who amid winter snows appeared barefoot on three successive days be fore the Tuscan castle in which sat Pope Gregory VII, refusing him absolution, or the capture, in Rome itself, by Henry V, of Pope Paschal II and all his cardinals. This so-called investiture quarrel ended in 1122 with the Con cordat of Worms, a compromise by which there were to be two investitures, one with the tem poral estates by the emperors, the other with the spiritual power by the Pope. It had taken 50 years to arrive at this simple solution of the matter. See INVESTITURE.