See Forschungen zur deutschen Geschichte, Bande ix. and x (Gottingen, 1862-1886); E. Dummler, Geschichte des ostfrdnkischen Reichs (Leipzig, 1887-1888); and Gesta Berengarii imperatori (Halle, 1871); and F. de Gingins-la-Sarra. Memoires pour servir i I'histoire de Provence et de Bourgogne Jurane (Zurich, 1851).
LOUIS IV., or V. (c. 1287-1347), surnamed the Bavarian Roman emperor and duke of Upper Bavaria, was the second son of Louis II., duke of Upper Bavaria and count palatine of the Rhine, and Matilda, daughter of the German king Rudolph I. Having lost his father in 1294 he inherited, jointly with his elder brother Rudolph, Upper Bavaria and the Palatinate but passed his time mainly at the court of the Habsburgs in Vienna, while his early experiences of warfare were gained in the campaigns of his uncle, the German king Albert I. He was soon at variance with his brother over their joint possessions Albert taking the part of Louis in this quarrel, Rudolph promised in 1301 to admit his brother to a share in the government of Bavaria and the Palatinate. When Albert was murdered in May 1308, Louis became a candidate for the German throne but his claim was not strongly supported. The new king, Henry VII., was very friendly with Rudolph, and as the promise of 1301 had not been carried out, Louis demanded a partition of their lands. Upper Bavaria was accordingly divided in 1310, and Louis received the north-western part of the duchy; but Rudolph refused to surrender any part of the Palatinate. In 1310, on the death of Stephen I., duke of Lower Bavaria, Louis undertook the guardianship of his two young sons. This led to a war between the brothers, which lasted till June 1313, when peace was made at Munich. Many of the nobles in Lower Bavaria, however, angered at Louis, called in the aid of Frederick I. (the Fair), duke of Austria; but he was defeated at Gammelsdorf on the gth of November 1313, a victory which not only led to peace, but conferred considerable renown on Louis.
In August 1313 the German throne had again become vacant, and Louis was chosen at Frankfort on the 2oth of October 1314 by a majority of the electors, and his coronation followed at Aix-la-Chapelle on the 25th of November. A minority of princes had, however, supported Frederick of Austria; and a war followed between the rivals, during which Louis was supported by the cities and the districts of the middle and lower Rhine. His embarrassments were complicated by a renewal of the dispute with his brother; but when this had been disposed of in 1317 by Rudolph's renunciation of his claims on upper Bavaria and the Palatinate in consideration of a yearly subsidy, Louis was able to give undivided attention to the war with Frederick, and obtained several fresh allies. On the 28th of September 1322 a battle was fought at Mvihldorf, which ended in a complete victory for Louis, owing mainly to the timely aid of Frederick IV. of Hohenzollern, burgrave of Nuremburg. Frederick of Austria was taken prisoner, but the struggle was continued by his brother Leopold until the latter's death in 1326. Attempts to enable the two kings to rule Germany jointly failed, and about 1326 Frederick returned to Austria, leaving Louis in undisputed possession of the country. Before this conclusion, however, a new enemy had taken the field. Supported by Philip V. of France in his desire to free Italy entirely from German influence, Pope John XXII. refused to recognize either Frederick or Louis, and asserted his own right to administer the empire during a vacancy. After the battle of Muhldorf Louis sent Berthold of Neifen, count of Marstetten, into Italy with an army, which soon compelled the papal troops to raise the siege at Milan. The pope threatened Louis with excommunication unless he resigned his kingdom within three months. The king thereupon appealed to a general council, and was placed under the papal ban on the 23rd of March 1324, a sentence which he answered by publishing his charges against the pope. In the contest Louis was helped by the Minorites, who were upholding against John the principal of clerical poverty, and by the writings of Marsilius of Padua (who dedicated to Louis his Defensor pacis), William of Occam, John of Jandun and others. Taking the offensive, Louis met his Ghibelline supporters at Trent and reached Italy in March 1327; and in May he received the Lombard crown at Milan. Although the pope renewed his fulminations Louis compelled Pisa to surrender, and was hailed with great rejoicing in Rome. On the 17th of January 1328 he was crowned emperor in St Peter's by Sciarra Colonna, a Roman noble; and he answered the continued attacks of Pope John by pronouncing his deposition, and proclaiming Peter of Corvara pope as Nicholas V. He then undertook an expedition against John's ally, Robert, king of Naples, but, disunion among his troops and scarcity of money and provisions, drove him again to Rome, where, finding that his exactions had diminished his popularity, he left the city, and after passing six months at Pisa, returned to Germany in January 1330. The struggle with the pope was renewed in Germany, and when a formidable league had been formed against Louis, his thoughts turned to a reconciliation. He was prepared to assent to very humiliating terms, and even agreed to abdicate; but the negotiations, which were prolonged by further demands on the part of the pope, were interrupted by his death in December 1334. John's successor, Benedict XII., seemed more anxious to come to an arrangement, but was prevented from doing so by the influence of Philip VI. of France. Overtures for peace were made to Philip, but without success; and in July 1337 Louis concluded an alliance with Edward III., king of England, and made active preparations for war. During these years his attention was also occupied by a quarrel with John, king of Bohemia, over the possession of Tirol, by a campaign in Lower Bavaria, and a futile expedition against Nicholas I., bishop of Constance. But although his position was shaken by the indifferent success which attended these campaigns, it was improved when the electors meeting at Rense in July 1338 banded themselves together to defend their elective rights, and when the diet at Frankfort confirmed a decree which declared that the German king did not need the papal approbation to make his election valid.
Louis devoted considerable thought and time to extending the possessions of the Wittelsbach family, to which he belonged. Tirol had for some time been a subject of contention between the emperor and other princes. The heiress of this county, Margaret Maultasch, had married John Henry, margrave of Moravia, son of King John of Bohemia. Having quarrelled with her husband, Margaret fled to the protection of Louis, who seized the opportunity to declare her marriage void and to unite her in 1342 with his son Louis. The emperor also increased his possessions by his own marriage. In 1322 his first wife, Beatrice, daughter of Henry III., count of Glogau, had died after thirteen years of married life, and Louis then married Margaret, daughter of William III., count of Holland. When her brother, count William IV., died childless in 1345, the emperor obtained possession of Holland, Zealand and Friesland. In 1341 he recovered a portion of the Palatinate, and soon deserted Edward of England and came to terms with Philip of France*. The acquisition of the territories, and especially of Tirol, had provided Louis with many enemies, prominent among whom were John of Bohemia and his family, that of Luxemburg. John, therefore, entered into an alliance with Pope Clement VI. The course of the war which ensued in Germany was such as to compel the emperor to submit to humiliating terms, though he stopped short of accepting the election of Charles, margrave of Moravia (afterwards the emperor Charles IV.) as German king in July 1346. Charles consequently attacked Tirol; but Louis, who appeared to have considerable chances of success, died suddenly at a bear-hunt near Munich on the nth of October 1347. He was buried in the Frauenkirche at Munich, where a statue was erected to his memory in 1622 by Maximilian I., elector of Bavaria, and where a second was unveiled in 1905. He had seven sons, three of whom were sub-equently electors of Brandenburg, and ten daughters.
Various estimates have been formed of the character of Louis. As a soldier he possessed skill as well as bravery, but he lacked perseverance and decision in his political relations. At one time haughtily defying the pope, at another abjectly craving his pardon, he seems a very inglorious figure; and the fact that he remained almost undisturbed in the possession of Germany in spite of the utmost efforts of the popes, is due rather to the political and intellectual tendencies of the