In that same year al-Mahdī built the Ruṣāfah Mosque and dug the moat that surrounded it. He also equipped a large army for the lands of India; they reached their destination the following year, and what happened to them will be mentioned in its proper place. During the year the viceroy of Sind, Maʿbad ibn al-Khalīl, died, and, on the advice of his vizier Abū ʿAbd Allāh, al-Mahdī appointed Rawḥ ibn Ḥātim in his stead.

That year al-Mahdī ordered the release of all prisoners save those jailed for bloodshed, for spreading corruption in the land, or for an outstanding private claim. Among those brought out of al-Muṭbaq (the dungeon) were Yaʿqūb ibn Dāʾūd, client of Banū Sulaym, and al-Ḥasan ibn Ibrāhīm ibn ʿAbd Allāh ibn Ḥasan. The Caliph directed that this Ḥasan be handed over to Naṣīr the chamberlain so that he might keep close watch on him.

Before his release al-Ḥasan had planned to escape from prison. When Yaʿqūb ibn Dāʾūd was freed, he informed the Caliph of the plot; al-Mahdī therefore removed al-Ḥasan from the prison and placed him in the custody of Naṣīr the chamberlain as a precaution. Thereafter Yaʿqūb enjoyed exceptional favour with al-Mahdī: he could enter the Caliph’s presence at night without permission, was entrusted with many affairs, and received one hundred thousand (100,000) dirhams. He remained in high esteem until al-Mahdī had al-Ḥasan ibn Ibrāhīm completely under control, whereupon Yaʿqūb’s standing collapsed. During the year the Caliph dismissed many provincial deputies and replaced them with others.

In this same year al-Mahdī married his cousin Umm ʿAbd Allāh, daughter of Ṣāliḥ ibn ʿAlī, freed his slave-girl al-Khayzurān and married her as well—she would later be the mother of al-Rashīd. A great fire also broke out that year among the boats moored on the Tigris at Baghdad.

When al-Mahdī assumed the caliphate he asked ʿĪsā ibn Mūsā—who had been designated heir-apparent after him—to renounce the succession, but ʿĪsā refused. He then sought leave to remain on an estate he owned near Kūfa, and the Caliph consented. At that time Rawḥ ibn Ḥātim was firmly installed as governor of Kūfa, and he wrote to al-Mahdī:

“ʿĪsā ibn Mūsā attends neither Friday nor congregational prayer with the people except for two months of the year; and when he does come, he rides his mounts through the gate of the mosque so that they drop their dung where the people pray.”

Al-Mahdī replied instructing him to erect wooden barriers across the alleyways so that no one could reach the mosque except on foot. Learning of this, ʿĪsā purchased—before the coming Friday—the house of al-Mukhtār ibn Abī ʿUbayd from his heirs. The house adjoined the mosque. From Thursday he would reside there; on Friday he would ride a donkey to the mosque gate, dismount, pray with the people, and he eventually settled in Kūfa with his household.

Al-Mahdī then pressed him hard to relinquish his claim, threatening him if he refused and promising him reward if he complied. ʿĪsā finally capitulated, whereupon the Caliph granted him vast estates and ten million (10,000,000) dirhams—some say twenty million (20,000,000)—and obtained the oath of allegiance for his two sons: first for Mūsā al-Hādī, then for Hārūn al-Rashīd, as will be detailed later.

That year the pilgrimage was led by Yazīd ibn Manṣūr, al-Mahdī’s maternal uncle. He had been governor of Yemen, but the Caliph entrusted him with the season and summoned him out of longing for him. Although al-Mahdī dismissed most provincial deputies, the following remained in office: in Ifrīqiyyah, Yazīd ibn Ḥātim; in Egypt, Muḥammad ibn Sulaymān Abū Ḍamrah; in Khurasan, Abū ʿAwn; in Sind, Bisṭām ibn ʿAmr; in Ahwāz and Fars, ʿImārah ibn Ḥamzah; in Yemen, Rajāʾ ibn Rūḥ; in Yamāmah, Bishr ibn al-Mundhir; in al-Jazīrah, al-Faḍl ibn Ṣāliḥ; in Medina, ʿUbayd Allāh ibn Ṣafwān al-Jumaḥī; and over Mecca and al-Ṭāʾif, Ibrāhīm ibn Yaḥyā; and over—