Born at Brescia towards the end of the eleventh century, date of death uncertain. If there is any truth in the statement made by Otto of Freisingen that Arnold completed his studies under the direction of Abelard, he must have gone to Paris about 1115. This would explain the affection towards the French master which he showed later in life, and we could easily understand how it came about that Abelard called him to his side after the Lateran Council of 1139, as St. Bernard intimates he did. In the judgment of some critics, however, there is not sufficient evidence for this first sojourn of Arnold in France, vouched for by Otto of Freisingen alone. Aspiring to a perfect life, Arnold at a tender age entered a convent of canons regular in his native city where he was ordained a priest and appointed prior or provost of his community. He was fitted for this high office by the austerity of his life, his detachment from earthly things, his love of religious discipline, the clearness of his intellect, and an originality and charm of expression that he brought to the service of a lofty ideal. Brescia yielded to his powerful influence, and in the course of some years Arnold was placed at the head of the reform movement then stirring the city. Precisely at this time Brescia, like most other Lombard cities, was entering upon the exercise of its municipal liberties. The government was in the hands of two consuls elected annually, but over against their authority that of the bishop, as principal landed proprietor, still remained. Hence arose between the rival forces inevitable conflicts in which were involved, together with political passions, the interests of religion. The sight of these conditions grieved Arnold and prompted him to apply a remedy. By constant dwelling on the evils which afflicted both city and Church, he came to the conclusion that their chief causes were the wealth of the clergy and the temporal power of the bishop. Was it not best, therefore, to take drastic measures at once to strip the monasteries and bishoprics of their wealth, and transfer it to laymen? Was not this the surest and quickest method of satisfying the civil authorities and of bringing back the clergy, by poverty, to the practice of evangelical perfection? To reduce this to a working theory, Arnold ventured to formulate the following propositions: "Clerics who own property, bishops who hold regalia [tenures by royal grant], and monks who have possessions cannot possibly be saved. All these things belong to the [temporal] prince, who cannot dispose of them except in favour of laymen."

The welcome given such teachings by the higher clergy may readily be inferred. Brescia passed through an alarming crisis, the various phases of which, owing to the brevity and obscurity of the documents at our disposal, can be but vaguely traced. From the testimony of various authors, however, Otto of Freisingen, St. Bernard, and John of Salisbury (supposed author of the "Historia Pontificalis"), the following facts are ascertained: a journey made by Bishop Manfred to Rome about 1138; an insurrection during his absence; the attempt of Arnold to prevent him on his return from taking possession of his see or temporal power; the appeal of the rebellious provost and his condemnation by Innocent II, at the Lateran Council, in 1139. Silence and exile were the penalties imposed on Arnold, and he was forbidden to return to Brescia without the express permission of the sovereign pontiff. The following year (1140) we find Arnold at Sens at the side of Abelard, who was about to make his last struggle against the champions of orthodoxy. St. Bernard awaited steadfastly both combatants, whose attack was turned to utter rout. In the words of the Abbot of Clairvaux, the "squire" was involved in the downfall of the "knight." The sentence passed upon Abelard by the council was confirmed by Innocent II. Arnold fared no better, for both were condemned to perpetual confinement in separate monasteries (Bull of 16 July, 1140). This decree, however, was never put into execution. While Abelard took refuge with Peter the Venerable, Abbot of Cluny, Arnold feigned retirement to Mont Sainte-Genevieve at Paris, where, however, he opened public courses of moral theology. He had but few disciples, and these, according to John of Salisbury, were so needy that they had to beg their daily bread. For that matter, however, this state of affairs accorded very well with the teachings of the new professor, who sharply censured the luxury of bishops and the worldly possessions of monks, and stigmatized wealth as the real virus that was infecting the Church. Arnold's attacks did not stop here. He was constantly haunted by the memory of his condemnation, and pursued unscrupulously with his taunts the detractors of Abelard. Thus he described the Abbot of Clairvaux as a man "puffed up with vainglory, and jealous of all those who have won fame in letters or religion, if they are not of his school." Thus boldly challenged, Bernard took up the gauntlet and denounced Arnold to Louis VII as "the incorrigible schismatic, the sower of discord, the disturber of the peace, the destroyer of unity," and brought it about that the "Most Christian King drove from the kingdom of France" him whom Italy had already exiled.

Arnold, compelled to flee, took refuge in Switzerland and fixed his abode at Zurich in the Diocese of Constance. The Abbot of Clairvaux continued active in pursuit, and some time afterwards (1143) we find the exile in Bohemia begging protection from a papal legate named Guy. This prelate - who must not be confounded with his namesake, disciple of Abelard, and later pope - received him with kindness and, touched by his misfortunes, treated him with great friendliness. This attitude vexed St. Bernard, who addressed to the legate a discourse on prudence, which, however, remained unheeded by Guy. There is every reason to believe that Arnold had given his host pledges of sincere submission, for this fact alone would explain his return to Italy, thenceforth open to him. This, too, explains the solemn abjuration which he made at Viterbo, before Pope Eugenius III, in 1145. The pontiff, on reconciling him with the Church, had imposed a form of penance then customary: fasts, vigils, and pilgrimages to the principal shrines of Rome. Unfortunately, in the air which Arnold was about to breathe there were floating the germs of revolt. Rome was endeavouring to re-establish her Senate to the detriment of the temporal power of the popes. A movement so thoroughly in keeping with the earlier thoughts and the secret desires of the repentant innovator could not but secure his sympathy and even his outspoken support. It was soon discovered that he was vilifying the clergy and disseminating from the Capital his plans for ecclesiastical reform. The Curia became the chief object of his attacks; he depicted the cardinals as vile hypocrites and misers playing among Christians the role of Jews and Pharisees. He did not even spare the pope. Eugenius III, whose gentle moderation this terrible reformer had but recently acknowledged, was suddenly transformed into the executioner of the Church, more concerned "with pampering his own body, and filling his own purse than with imitating the zeal of the Apostles whose place he filled." In particular, Arnold reproached the pope for relying on physical force, and for "defending with homicide" his rights when contested. Eugenius III was forced to leave the Eternal City, and for some time (1146-49) Roman democracy triumphed under Arnold of Brescia. Though excommunicated by the pope (15 July, 1148), Arnold did not despair of his position. By degrees, however, his revolutionary programme took on another character. The abolition of the temporal power of the papacy was now only the first of his demands; the second contemplated the subordination of the spiritual to the civil power. Wetzel, one of his disciples presumed to offer to King Conrad III the keys of the Castle of Sant' Angelo, so that the German emperors might have the future disposal of the tiara and the government of Rome. Arnold's policy, at first republican, thus ended in downright imperialism. Frederick Barbarossa, however, Conrad's successor, refused to support the schemes of the Roman agitators. With much cleverness and tact, Eugenius III won over the emperor to the cause of the papacy. Arnold was thus rendered helpless. The senatorial elections of November, 1152, had turned against him, and marked the beginning of his fall.

Little is known of Arnold during the brief reign of Anastasius IV (July, 1153 - December, 1154), but the election of Adrian IV was fatal to his cause. He had fallen into the hands of Odo, Cardinal-Deacon of St. Nicholas in carcere Tulliano, but was freed by the Viscounts of Campagnatico, and found for some years a safe refuge in their territory. They "looked on him as a prophet" inspired by God. However, as in an agreement between Adrian and Frederick Barbarossa, the pope obtained the emperor's promise that he would seize the person of Arnold and remove him, willing or unwilling, from the custody of the Viscounts of Campagnatico. Frederick did not hesitate to make and keep this promise, and accordingly Arnold was handed over to the Curia. It is quite difficult to give an exact account of the trial of Arnold. According to the story recorded by Gerhoh de Reichersperg, he was secretly removed from the ecclesiastical prison and put to death by the servants of the prefect of Rome, who had suffered great injuries from the revolution fomented by Arnold. It is very probable, however, that the Curia had a larger share in his condemnation. One analyst goes so far as to say that the pope personally ordered him to be hanged. Another writer affirms, with more semblance of truth, that Adrian confined himself to demanding Arnold's degradation, so that he might be delivered over to the secular power. According to the author of a poem recently discovered (and he seems to be well informed), Arnold when brought in sight of the gallows faced his death courageously. When urged to recant his teachings, he answered that he had nothing to withdraw, and was ready to suffer death for them. He asked only for a brief respite to pray and beg Christ's pardon for his sins. After a short mental prayer he gave himself up to the executioner, and offered his head to the noose. After hanging from the gallows for a short time, his body was burned, and the ashes thrown into the Tiber, "for fear", says one chronicler, "lest the people might collect them and honour them as the ashes of a martyr."

"Forger of heresies," "sower of schisms," "enemy of the Catholic Faith," "schismatic," "heretic," such are the terms used by Otto of Freisingen, by the author of the "Historia Pontificalis," by the Abbot of Clairvaux, by Eugenius III, and Adrian IV to stigmatize Arnold. Given the vagueness of these characterizations, it is not easy to specify the dogmatic errors into which the innovator fell. Otto of Freisingen echoes a rumour according to which Arnold held offensive views on baptism and the Eucharist. His contemporaries (notably St. Bernard, who pursued so bitterly the "squire" of Abelard) lay nothing of the kind to his charge. The abbot of Clairvaux in one of his letters accuses Arnold of being "an enemy of the Cross of Christ." But must we conclude from this that Arnold was a follower of Pierre de Bruys, who condemned the adoration of the Cross? It is much more probable that the words of St. Bernard are to be taken broadly or in a metaphorical sense. In reality it was in practical matters that Arnold showed himself inimical to the teachings accepted at his time. He began by condemning the abuses occasioned by the wealth of the churchmen, an act which in itself placed him in the class of true reformers; St. Bernard and Gerhoh de Reichersperg said the same thing. But Arnold did not stop at this; he went so far as to deny the very principle of proprietary right as claimed by the Church, and thereby assailed the temporal power of the papacy. "All earthly possessions belong to the prince, the pope should relinquish the government of Rome; bishops, priests, and monks can own nothing without incurring the penalty of eternal damnation." On all these various points the innovator, to say the least, was plainly guilty of temerity. And since he clashed with a hierarchy that was not prepared to sanction his views, he ended by questioning its authority. According to him, the Church had become corrupt in the persons of covetous and simoniacal priests, bishops, and cardinals, and was no longer the true Church. "The pope," he says, "is no longer the real Apostolicus, and, as he does not exemplify in his life the teachings of the Apostles, there is no obligation of reverence and obedience towards him." The unworthy clergy lose the right of administering the sacraments, and the faithful need no longer confess" to them. It is sufficient that they confess to one another. If it be true, as stated by the anonymous author of the poem above quoted, that Arnold had fallen into these errors, the schismatical and heretical character of his teachings remains no longer doubtful. His disciples, i.e. those whom the thirteenth-century documents call the Arnoldists, or Arnaldists, taught other errors no less serious, for which, however, Arnold cannot justly be held responsible.

For the original authorities concerning ARNOLD, see Historia Pontificalis (the author of which is probably JOHN OF SALISBURY) in Mon. Germ. Hist. (fol., Hannover, 1868), XX, 537, 538; OTTO OF FREISINGEN, Gesta Friderici imperatoris, II, 20-23, in Mon. Germ. Hist., XX, 366, 367, 403, 404; GUNTHER, Ligurinus, verses 262-348, in P.L., CCXII, 369-371; Gesta per imperatorem Fridericum Barbam Rubeam in partibus Lombardie et Italie, fragment of an anonymous poem, published by E. MONACI in Archivio della societa romana di storia patria (Rome, 1878), I, 466-474; Annales Augustani Minores, in Mon. Germ. Hist., X, 8; BOSO, Vita Hadriani IV, in DUCHESNE, Liber pontificalis (Paris, 1889), II, 390; Letters of Eugenius III, in BARONIUS, Annales ecclesiastici (ad. ann. 1148, No. 38); GERHOH OF REICHERSPERG, De Investigatione Antichristi, I, xlii; ed. SCHEIBELBERGER (1875), I, 87-89; ST. BERNARD, Epist., clxxxix, cxcii, cxcv, cxcvi, in P.L. CLXXXII, 354-357, 358, 359, 361-362, 363, 364; Letter of WETZEL, the disciple of ARNOLD, and an anonymous letter [possibly ARNOLD's] in MARTENE AND DURAND, Veterum scriptorum et monumentorum. . .amplissima collecito (Paris, 1724), II, 399, 400, 554-557; ANON., Commentaire des causes heretiques, inserted in HUGUCCIO'S Summa Decreti, 1211-15, xxix of Cause 23, quest. 4. cf. TANON, Histoire des tribunaux de l'Inquisition (Paris, 1893), 456, note 2; BUONACORSO OF MILAN (end of twelfth century), Vita hoereticorum, in P.L., CCIV, 791-792; SCAELCHIN, Arnold von Brescia (Zurich, 1872); BENVICENNI, Arnaldo da Brescia, condennato a morte per ordine di papa Adriano IV (Florence, 1873); GIESEBRECHT, Arnold von Brescia (Munich, 1873, Italian translation by ODORICI, Brescia, 1877); DE CASTRO, Arnaldo da Brescia e la rivoluzione romana del XII secolo (Leghorn, 1875); G. GAGGIA, Arnaldo da Brescia (Brescia, 1882); E. VACANDARD, Arnauld de Brescia, in the Revue des quest. histor. (Paris, 1884) XXXV, 52-114; cf. Vie de Saint Bernard (Paris, 1895), II, 235-245, 257, 258, 467-469); F. TOCCO, L'eresia nel medio evo (Florence, 1884), 231-256; and Quel che non c'e nella Divina Commedia, o Dante e l'eresia (Bologna, 1899); HAUSRATH, Arnold von Brescia (Leipzig, 1891); MICHELE DI POLO, Due novatori del XII secolo (Florence, 1894), 79 sqq.; E. COMBA, I nostri protestanti: Avanti la Riforma (Florence, 1895), I, 173 sq.; FECHTRUP, Arnold von Brescia in Kirchenlex., I, 1419-20; DEUTSCH, Arnold von Brescia in Realencyclopaedie fuer protest. Theologie und Kirche (3d ed., Leipzig, 1897), II, 117-122; VERNET, Arnaud de Brescia in Dict. de theol. cath. (Paris, 1903), I, 1972-75. For other less important references see: CHEVALIER, Repertoire des sources hist. du moyen age (2d ed., 320, 321).

E. VACANDARD