Strangely enough, some of his disciples persisted in believing in him; "they preferred to die rather than renounce their belief," says an historian of the time. They were handed over to the secular arm and perished at the stake. In decreeing this penalty, the civil power was undoubtedly influenced by the example of Robert the Pious.
It is easy to determine the responsibility of the Church, i.e., her bishops and priests, in this series of executions (1020 to 1150). At Orleans, the populace and the king put the heretics to death; the historians of the time tell us plainly that the clergy merely declared the orthodox doctrine. It was the same at Goslar. At Asti, the Bishop's name appears with the names of the other nobles who had the Cathari executed, but it seems certain that he exercised no special authority in the case. At Milan, the civil magistrates themselves, against the Archbishop's protest, gave the heretics the choice between reverencing the cross, and the stake.
At Soissons, the populace, feeling certain that the clergy would not resort to extreme measures, profited by the Bishop's absence to burn the heretics they detested. At Liège, the Bishop managed to save a few heretics from the violence of the angry mob. At Cologne, the Archbishop was not so successful; the people rose in their anger and burned the heretics before they could be tried. Peter of Bruys and the Manichean at Cambrai were both put to death by the people. Arnold of Brescia, deserted by fortune, fell a victim to his political adversaries; the prefect of Rome was responsible for his execution.[1]
[1] The case of Arnold, however, is not so clear. The _Annales Augustani minores_ (_Mon. Germ. SS_., vol. x, p. 8) declare that the Pope hanged the rebel. Another anonymous writer (cf. Tanon, _Hist. des tribunaux de l'Inq. en France_, p. 456, n. 2) says with more probability, that Adrian merely degraded him. According to Otto of Freisingen (_Mon. Germ. SS_., vol. xx, p. 404), Arnold _principis examini reservatus est, ad ultimum a præfecto Urbis ligno adactus_. Finally, Geroch de Reichersberg tells us (_De investigatione Antichristi_, lib. i, cap. xiii, ed. Scheibelberger, 1875, pp. 88-89) that Arnold was taken from the ecclesiastical prison and put to death by the servants of the Roman prefect. In any case, politics rather than religion was the cause of his death.