Mirza Muhammad Hashim was the youngest son of Haji Ahmad, the elder brother of Alivardi Khan.
Hashim's paternal grandfather Mirza Muhammad Madani, who was of either Arab or Turkic descent, was the son of a foster-brother of the Mughal emperor Aurangzeb.
[3] Due to their royal background, Hashim and his family all worked for the administration of his cousin, the Nawab of Bengal Shuja-ud-Din Muhammad Khan.
After the ascension of Alivardi Khan as the Nawab of Bengal in November 1740, he was made the Governor of Bihar and given the title of Haibat Jang.
However, the rebels later got the upper hand in Patna and assassinated Zain ud-Din Ahmed Khan on 13 January 1748.