838; he is also said to have pushed through an irrigation canal project in Khurasan, and following a large fire in Baghdad he was able to convince the caliph to entrust him with distributing five million dirhams for the relief of the citizens there. Ibn Abi Du'ad additionally took part in the move to the new capital of Samarra in 836, where he received a land allotment in the central city, and in 840 he presided over the heresy trial of the disgraced general al-Afshin. Under al-Wathiq Ibn Abi Du'ad remained influential under al-Mu'tasim's son and successor al-Wathiq (r. 842–847), who similarly maintained the doctrine that the Qur'an had been created. For the majority of al-Mu'tasim's reign, the had generally been only lightly enforced, although Ibn Abi Du'ad and his allied qadis had escalated their activities in the last year of the caliph's life. With the accession of al-Wathiq, however, the new caliph ordered that the severity of the be increased, giving advocates of the inquisition approval to proceed with vigor. At the beginning of al-Wathiq's reign, Ibn Abi Du'ad appointed several new qadis to Baghdad who supported the , and in the provinces there was a marked increase of persecutions against individuals who were considered dissenters. In 845 the was even extended to Muslim prisoners held by the Byzantines, when Ibn Abi Du'ad sent an agent to test their opinion on Qur'anic createdness and ransomed only those who supported it, leaving those who did not in Byzantine custody. Al-Wathiq's continued adherence to the belief of the created Qur'an eventually prompted a traditionalist backlash, which manifested itself in 846 as a planned popular revolt in Baghdad. The plot was discovered ahead of time, however, and its ringleader Ahmad ibn Nasr al-Khuza'i was arrested and sent to al-Wathiq in Samarra, where he was questioned on his beliefs regarding the nature of the Qur'an. Ahmad's statements during the interrogation enraged al-Wathiq, and despite Ibn Abi Du'ad's reluctance to have him killed the prisoner was personally executed by the caliph and his soldiers. The public death of Ahmad only further increased populist agitation in Baghdad against the caliph's religious policy, and Ahmad was soon turned into a martyr by supporters of orthodoxy. Under al-Wathiq, the rivalry between Ibn Abi Du'ad and the vizier Ibn al-Zayyat continued. During a general crackdown against the state bureaucracy in 843-4, Ibn al-Zayyat took action against the chief