and Wahb ibn Jarir ⦗1⦘; and Yazid ibn Harun, the teacher of Imam Ahmad ⦗2⦘.

[Then came the year 207 AH]

In that year ʿAbd al-Rahman ibn Ahmad ibn ʿAbd Allah ibn Muhammad ibn ʿUmar ibn ʿAli ibn Abi Talib rose up in the district of ʿAk in Yemen, calling the people to pledge allegiance to the “Approved One” from the Household of Muhammad, peace and blessings be upon him. The governors of Yemen had been treating the populace unjustly, so when ʿAbd al-Rahman appeared the people rallied to him and gave him their bayʿa.

When the report reached al-Maʾmun he dispatched Dinar ibn ʿAbd Allah at the head of a large army, carrying a guarantee of safety for ʿAbd al-Rahman should he listen and obey. They performed the pilgrimage together, then proceeded to Yemen. On arriving, Dinar sent him the writ of amān; he accepted it, complied, came forward, and placed his hand in Dinar’s. He then travelled with him to Baghdad and donned the black garb.

That same year:
Tahir ibn al-Husayn ibn Musʿab, the governor of all Iraq and of Khurasan, passed away. He was found dead in his bed after performing the late ʿIshaʾ prayer and lying down. When he delayed coming out for the dawn prayer, his family grew concerned; his brother and his uncle entered and found him lifeless.

When news of his death reached al-Maʾmun he said, “For the hands and the mouth—praise be to Allah who advanced him and left us behind.” ⦗3⦘

Al-Maʾmun had been told that on one occasion Tahir delivered the sermon without praying for him from the pulpit. Even so, he appointed Tahir’s son ʿAbd Allah in his stead and added al-Jazirah and Syria to his jurisdiction. ʿAbd Allah left Khurasan under the care of his brother Ṭalḥah ibn Tahir for seven years; when Ṭalḥah died, ʿAbd Allah assumed full authority over all those lands. His deputy in Baghdad was Ishaq ibn Ibrahim.

It was this same Tahir ibn al-Husayn who had wrested Baghdad and the whole of Iraq from al-Amin ibn al-Rashid and killed him, thereby securing the realm for al-Maʾmun, as we mentioned under the year 195 AH. On one occasion Tahir entered upon al-Maʾmun and requested a favor, which the caliph granted. Al-Maʾmun then looked at him, and his eyes filled with tears. Tahir asked, “What makes you weep, Commander of the Faithful?” but he would not say. Tahir therefore gave the servant Husayn two hundred thousand dirhams to learn the reason. The servant said, “Tell no one of this, or I will kill you. I was reminded of my brother’s death and the humiliation he suffered at Tahir’s hands. By Allah, Tahir shall not escape from me what he hates.”