Tahir ibn Husayn (died 822) was a general and governor during the Abbasid

Abbasid

The Abbasid Caliphate or, more simply, the Abbasids , was the third of the Islamic caliphates. It was ruled by the Abbasid dynasty of caliphs, who built their capital in Baghdad after overthrowing the Umayyad caliphate from all but the al-Andalus region....

 caliphate

Caliphate

The term caliphate, "dominion of a caliph " , refers to the first system of government established in Islam and represented the political unity of the Muslim Ummah...

. Specifically, he served under al-Ma'mun

Al-Ma'mun

Abū Jaʿfar Abdullāh al-Māʾmūn ibn Harūn was an Abbasid caliph who reigned from 813 until his death in 833...

 and led the armies that would defeat al-Amin

Al-Amin

Muhammad ibn Harun al-Amin , Abbasid Caliph. He succeeded his father, Harun al-Rashid in 809 and ruled until he was killed in 813.-Caliph:...

, making al-Ma'mun the caliph. He was born in Phoshang which is a village in ancient city of Herat

Herat

Herāt is the capital of Herat province in Afghanistan. It is the third largest city of Afghanistan, with a population of about 397,456 as of 2006. It is situated in the valley of the Hari River, which flows from the mountains of central Afghanistan to the Karakum Desert in Turkmenistan...

 (then Khorasan

Greater Khorasan

Greater Khorasan or Ancient Khorasan is a historical region of Greater Iran mentioned in sources from Sassanid and Islamic eras which "frequently" had a denotation wider than current three provinces of Khorasan in Iran...

 present day Afghanistan

Afghanistan

Afghanistan , officially the Islamic Republic of Afghanistan, is a landlocked country located in the centre of Asia, forming South Asia, Central Asia and the Middle East. With a population of about 29 million, it has an area of , making it the 42nd most populous and 41st largest nation in the world...

).

Afterwards, Tahir was made governor of the eastern Abbasid

Abbasid

The Abbasid Caliphate or, more simply, the Abbasids , was the third of the Islamic caliphates. It was ruled by the Abbasid dynasty of caliphs, who built their capital in Baghdad after overthrowing the Umayyad caliphate from all but the al-Andalus region....

 lands, effectively making him governor of Persia

Abbasid

The Abbasid Caliphate or, more simply, the Abbasids , was the third of the Islamic caliphates. It was ruled by the Abbasid dynasty of caliphs, who built their capital in Baghdad after overthrowing the Umayyad caliphate from all but the al-Andalus region....

. Tahir later declared independence from the Abbasid empire in 822 by omitting any mention of al-Ma'mun during a Friday sermon. However, he died the same night and al-Ma'mun appointed Tahir's son to continue at his father's post. This established the Tahirid dynasty

Tahirid dynasty

The Tahirid Dynasty, was a Persian dynasty that governed from 820 to 872 over the northeastern part of Greater Iran, in the region of Khorasan . The dynasty was founded by Tahir ibn Husayn, a leading general in the service of the Abbasid caliph al-Ma'mun...

, which ruled a semi-autonomous state in eastern Persia.

Tahir commissioned the Christian theologian, Theodore Abu-Qurrah

Theodore Abu-Qurrah

Theodore Abū Qurrah was a 9th century Christian Arab theologian who lived in the early Islamic period.Biography=He was born around 750 AD in the city of Edessa, in northern Mesopotamia, and was the Chalcedonian or Melkite bishop of the nearby city of Harran between 795 and 812...

 (died c. 830) to translate the pseudo-Aristotelian De virtutibus animae into Arabic from Greek.