The persecution of the Donatists was an event not less favourable to the designs of Genseric. Seventeen years before he landed in Africa a public conference was held at Carthage by the order of the magistrate. The Catholics were satisfied that, after the invincible reasons which they had alleged, the obstinacy of the schismatics must be inexcusable and voluntary; and the emperor Honorius was persuaded to inflict the most rigorous penalties on a faction which had so long abused his patience and clemency. Three hundred bishops, with many thousands of the inferior clergy, were torn from their churches, stripped of their ecclesiastical possessions, banished to the islands, and proscribed by the laws, if they presumed to conceal themselves in the provinces of Africa. By these severities, which obtained the warmest approbation of St. Augustine, great numbers of Donatists were reconciled to the Catholic church; but the fanatics, who still persevered in their opposition, were provoked to madness and despair; the distracted country was filled with tumult and bloodshed. The armed troops of Circumcellions alternately pointed their rage against themselves or against their adversaries; and the calendar of martyrs received on both sides a considerable augmentation. Under these circumstances Genseric, a Christian but an enemy of the orthodox communion, showed himself to the Donatists as a powerful deliverer, from whom they might reasonably expect the repeal of the odious and oppressive edicts of the Roman emperors. The conquest of Africa was facilitated by the active zeal or the secret favour of a domestic faction; the wanton outrages against the churches and the clergy, of which the Vandals are accused, may be fairly imputed to the fanaticism of their allies; and the intolerant spirit which disgraced the triumph of Christianity contributed to the loss of the most important province of the West.
The court and the people were astonished by the strange intelligence that a virtuous hero, after so many favours and so many services, had renounced his allegiance and invited the barbarians to destroy the province intrusted to his command. The friends of Boniface, who still believed that his criminal behaviour might be excused by some honourable motive, solicited, during the absence of Aëtius, a free conference with the count of Africa; and Darius, an officer of high distinction, was named for the important embassy. In their first interview at Carthage, the imaginary provocations were mutually explained; the opposite letters of Aëtius were produced and compared, and the fraud was easily detected. Placidia and Boniface lamented their fatal error; and the count had sufficient magnanimity to confide in the forgiveness of his sovereign, or to expose his head to her future resentment. His repentance was fervent and sincere; but he soon discovered that it was no longer in his power to restore the edifice which he had shaken to its foundations. Carthage and the Roman garrisons returned with their general to the allegiance of Valentinian, but the rest of Africa was still distracted with war and faction; and the inexorable king of the Vandals, disdaining all terms of accommodation, sternly refused to relinquish the possession of his prey. The band of veterans who marched under the standard of Boniface and his hasty levies of provincial troops were defeated with considerable loss; the victorious barbarians insulted the open country; and Carthage, Cirta, and Hippo Regius were the only cities that appeared to rise above the general inundation.
[430-431 A.D.]