In 1799, he was appointed governor of the town of Semnan and later, in 1802, of the Khorasan province, where he successfully recaptured its provincial capital Mashhad from the rebellious Afsharid prince Nader Mirza Afshar in 1803.

[1] In 1799, Mohammad Vali Mirza was appointed as the governor of the town of Semnan,[1][5] thus succeeding Fath-Ali Shah's brother Hossein Qoli Khan Qajar, who had been dissatisfied with his post.

[6] In the autumn of 1802, Mohammad Vali Mirza was appointed as the governor of Khorasan by Fath-Ali Shah, who was at the time besieging Mashhad,[7] the provincial capital of the province.

[9] Eshaq Khan Qaraei-Torbati, leader of the Qarai tribe, was rewarded by Mohammad Vali Mirza with the title of sardar and one of his daughters in marriage.

[13] The authority of the Iranian provincial governors was limited the nearby areas of Mashhad, Nishapur, Sabzevar, and Torshiz, even though Khorasan was nominally a part of Iran.

Many local leaders had established their own domain in the late 18th-century as a result of the political vacuum left by the decline of Durrani power and the vulnerability of Mashhad's Afsharid rulers.

The Qarai tribe, who ruled over Torbat-e Heydarieh, an agricultural region south of Mashhad that British observers referred to as "one of the most prosperous towns" in Khorasan, were the most prominent amongst these local leaders.

Officials demonstrating loyalty and appointees to lower positions were recipients of numerous khilats from Fath-Ali Shah and Mohammad Vali Mirza.

The Naqshbandi murshid (teacher) Sufi Islam and the leader of the Sunni clergy in Herat, Hajji Mulla Musa, also supported Firuz al-Din Mirza.

Mohammad Khan Qajar then besieged Herat, forcing Firuz al-Din Mirza to surrender after forty days and agree to pay two years worth of income.

[10] Firuz al-Din Mirza's inability to pay tribute and his suspected plans to regain control of Ghuriyan prompted the next Iranian attack against Herat in July 1811.

The author of Nasekh-ol-tavarikh-e salatin-e Qajariyeh considered this to have been caused by his treatment towards them; "Whenever he detected a hint of rebelliousness among the great ones… he would fly into a rage and abuse their ancestors and descendants with filthy language.

The decision to get rid of Mohammad Vali Mirza was made by Eshaq Khan and the other Khorasani aristocrats at a meeting held in the Gorgan Plain.

He also made an effort to discredit Mohammad Vali Mirza at the royal court by suggesting in multiple messages that the appointment of a new and competent governor was the only way to end the conflict with Khorasan's aristocrats.

[20] In 1816, he and his son Hossein Qoli Khan Qarai (who was now the governor of Torshiz), were strangled at the court in Mashhad under the orders of Mohammad Vali Mirza, who witnessed it.

[20][21] Mohammad Vali Mirza's circumstances did not improve once his biggest opponent was removed, since instability continued to spread throughout Khorasan, especially in the areas that were disputed between Mashhad and Herat.

"[23] According to modern Iranian historian Fatema Soudavar Farmanfarmaian; "Khorasan was indeed a trouble spot managed commendably by the Prince, though the discontent resulting from the rash execution of the Qara'is inflamed the tribes who would plague the province for many years to come.