“Yes, by Allah! And should that come to pass I shall renew relations with those you have estranged, grant justice to those you have wronged, and marry my sons to your daughters.”

Al-Hādī replied, “That is exactly what I expected of you.” Hārūn rose and kissed his hand, whereupon al-Hādī swore that he must sit with him upon the throne; so he sat beside him. The Caliph then ordered that one million dinars be given to him, that he be allowed to enter the treasuries and take whatever he wished, and that, when the land-tax revenue arrived, half of it be handed over to him. All of this was carried out, and al-Hādī was well pleased with al-Rashīd.

After the reconciliation al-Hādī travelled to Ḥadīthah in the district of Mosul, then returned from there and died at ʿĪsābādh (1) on the night of Friday, the fifteenth of Rabiʿ al-Awwal; some say it was at the end of the year 170 AH. He was twenty-three years old, and his caliphate had lasted six months and twenty-three days. He was tall, handsome, and fair-skinned, though his upper lip was slightly drawn back.

On that very night a caliph died—al-Hādī; a caliph was invested—al-Rashīd; and a caliph was born—al-Maʾmūn ibn al-Rashīd. Their mother al-Khayzurān had said early that night, “It has reached me that a caliph will be born, a caliph will die, and a caliph will be invested.” It is said that she had heard this forecast from al-Awzāʿī some time before, and it pleased her greatly.

It is also said that she poisoned her son al-Hādī out of fear for her other son al-Rashīd, for al-Hādī had distanced and sidelined her while favoring his concubine Khāliṣah and drawing her close. Allah knows best.

The following is a brief account of al-Hādī’s life (2):

He is Mūsā ibn Muḥammad al-Mahdī ibn ʿAbd Allah al-Manṣūr ibn Muḥammad ibn ʿAlī ibn ʿAbd Allah ibn ʿAbbās, Abū Muḥammad al-Hādī. He assumed the caliphate in Muḥarram 169 AH and died on the fifteenth of Rabiʿ al-Awwal—or, according to some, Rabiʿ al-Ākhir—170 AH, at the age of twenty-three, though some say twenty-four or twenty-six; the first view is the most reliable. It is said that no one before him had become caliph at so young an age. He was comely, handsome, fair-skinned, and tall, possessed of great strength, able to leap onto a mount while wearing two coats of mail. His father used to call him “my two sweet-basils.”

ʿĪsā ibn Dāʾib relates: “I was one day in the presence of al-Hādī when a basin was brought in containing the severed heads of two slave-girls who had been slaughtered and dismembered. I had never seen faces more beautiful, hair so lovely—in which pearls and jewels were arrayed—nor smelled a fragrance so sweet.

“The Caliph said to us, ‘Do you know the story of these two?’

“I replied, ‘No.’

“He said, ‘It was reported to me that one of them would mount the other and they would commit indecency together, so I ordered a servant to watch them. He later came to me and said, “They are together,” so I went and found them…’