Khazar general of the mid 700s, sometimes referred to as As Tarkhan, who led an invasion of 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....

 territories in Armenia

Armenia

Armenia , officially the Republic of Armenia , is a landlocked mountainous country in the Caucasus region of Eurasia...

, Caucasian Albania

Caucasian Albania

Albania is a name for the historical region of the eastern Caucasus, that existed on the territory of present-day republic of...

 and northwestern Persia

Iran

Iran , officially the Islamic Republic of Iran , is a country in Southern and Western Asia. The name "Iran" has been in use natively since the Sassanian era and came into use internationally in 1935, before which the country was known to the Western world as Persia...

. Scholars have debated over whether Ras Tarkhan

Tarkhan

Tarkhan is an ancient Central Asian title used by various Indo-European Tarkhan (Old Turkic Tarqan; Mongolian: Darkhan; ; ; ; alternative spellings Tarkan, Tarkhaan, Tarqan, Tarchan, Tarxan, Tarcan or Targan) is an ancient Central Asian title used by various Indo-European Tarkhan (Old Turkic...

 is a name or a title. As Tarkhan, used as a title, would mean "general of the Alans

Alans

The Alans, or the Alani, occasionally termed Alauni or Halani, were a group of Sarmatian tribes, nomadic pastoralists of the 1st millennium AD who spoke an Eastern Iranian language which derived from Scytho-Sarmatian and which in turn evolved into modern Ossetian.-Name:The various forms of Alan —...

", possibly indicating a role as commander of Alan mercenaries or auxiliaries.
According to Zeki Validi Togan and Peter Benjamin Golden

Peter Benjamin Golden

Peter Benjamin Golden is Professor of History at Rutgers University. He earned his bachelors degree from CUNY Queens College in 1963 and his M.A. and PhD in History from Columbia University in 1968 and 1970, respectively...

, Ras Tarkhan came from a clan called Khatiriltber.