[7] In 1645 Allami Sa'adullah was granted the post of Diwan-I-Khalisa, he was also given the charge of drafting royal orders, he worked for 46 days in this position before being appointed as the Grand Vizier of the Empire, with his mansab reaching 5000 Zat and 1500 Sawar.

[8][2] In the year 1645, the incumbent Prime Minister Islam Khan II was made to vacate his position and take up governorship in the Deccan region by Shah Jahan.

By this time, Saadullah Khan had become widely respected for his intelligence and talent, which had enabled his ascent in the Mughal administration despite a lack of political or family connections.

[10] He was subsequently rewarded with a Khilat and an increase of 1000 in his mansab for managing the situation efficiently and saving the Mughals from a disaster in Balkh region.

Sa'adullah Khan is described as a "man esteemed by the king and the whole court" by the Italian Traveler Nicolas Manucci, he also relates the events of the rebellion of the Bundela Rajputs which was successfully put down thanks to the cunningness of the Vizier.

[15] A Dutch envoy Joan Tack accused the Grand Vizier of harboring an inherent hostility toward Europeans, notably citing his role in expelling the Portuguese from Bengal.

In this portrayal, Sa‘dullah Khan is cast as the de facto ruler of the empire, wielding near-autocratic control over its political machinery, symbolizing the centralized authority of the Mughal state.