According to historian Ashirbadi Lal Srivastava, Khan was born in c. 1680 and his birth name was Mir Muhammad Amin.

[3] One of their ancestors was Mir Shamsuddin, a sayyid (descendant of Muhammad) and a kazi (Islamic judge) in Nishapur.

Sultan Husayn (the last Safavid monarch) alienated his court's nobility, and Khan's family was reduced to poverty.

[6] To try his luck in India, Khan's father and elder brother migrated to Bengal in late 1707 during the reign of Mughal Emperor Bahadur Shah I.

With the patronage of Muhammad Jafar, a friend of Farrukhsiyar, Khan succeeded in getting a mansab of a hazari (1,000 horses) and became the commander of the Wala-Shahi regiment.

[13] The Rajput and Jat zamindars (landlords) were rebelling; Khan began recruiting more troops, and borrowed from the wazir (minister) of the province.

With the help of auxiliary troops, Khan suppressed the rebellion in the area; the zamindars, attacked one by one, were forced to surrender.

After restoring law and order within six months of his appointment, Khan was promoted to the rank of 15 sad-izat (commander of 1,500 horses) in the army.

A few days before Shah began his journey, a conspiracy was hatched at the royal camp to kill Hussain Ali Khan.

[17] The conspirators met frequently to outline a plan to assassinate Hussain Ali Khan,[18] who was killed by Haidar Beg Daulat on 8 October 1720.

[19] The following day, Muhammad Shah held a royal durbar and rewarded Khan and his co-conspirators.

[20] He was given the title Saadat Khan Bahadur (lord of good fortune), and was promoted to 5,000 zat and 3,000 horses.

[21] Khan was promoted to a rank of 6,000 zat and 5,000 horses, and was appointed governor of Akbarabad province (present-day Agra), on 15 October 1720.

[26] Khan gathered his troops including Kalika Prasad Tandon[27] and recruited more before leaving for the province.

Muhammad Khan Bangash, the Hindustani Pathan chief, gave him information about the strength of Shaikhzadas (a community which ruled Lucknow).

[30] Khan tried to solve Awadh's fiscal and jagirdar problems, sending agents to assess crop yields.

He soon realized that, except for the zamindars, no one (including the local officials) welcomed his scheme; jagirdar agents tried to prevent its implementation.

[32] This scheme stabilised provincial administration, since the jagirdars no longer had to send their staff to the fields; the amils (appointed by the governor) were now accountable to him, and local officials were to approach them directly to resolve disputes.

[33] In 1730, Burhan-ul-Mulk sent Mir Muhammad Salah Khan Baraha and Sayyid Munawwar Ali Tirmizi of Bilgram to the qasbahs around Lucknow to recruit men for his army.

When he heard the news, Khan picked up the sword he had laid in front of Muhammad Shah and asked his permission to attack the Persian army.

According to historian Hari Charan Das, the Mughal emperor distrusted the Persian Khan and made him swear allegiance in the name of the Quran.

Asked why he fought against a Persian of the same religion (Shia Islam), Khan replied that he did not want to betray the Mughal emperor.

He asked Khan to outline a plan in which he could extort money from Muhammad Shah and return to Persia to fight the Turks.

[41] On 25 February, Muhammad Shah made Ghazi ud-Din Khan Feroze Jung II, the eldest son of Nizam-ul-Mulk, mir bakshi (equivalent to an army's paymaster general).

), a daughter of Khwaja Zachariah, a descendant of Khwaja Ahrar.He had also married Khadija Khanum Sahiba, a former slave girl from the household of Sayyid Talib Muhammad Khan, presented to him in the dower of the latter's daughter.He had five daughters.He gave his eldest daughter in marriage to his nephew, Muhammad Muqim, better known as Safdar Jung.

[47] All subsequent Nawabs and Kings of Awadh down to Wajid Ali Shah are thus descended from Sadat Khan through his daughter.