Who was the ruler of Bengal before the Battle of Buxar?

Who was the ruler of Bengal before the Battle of Buxar?

بکسر (1764) کی لڑائی کے دوران بنگال کا حکمران کون تھا؟
Explanation

Mir Qasim was the Nawab of Bengal before the Battle of Buxar in 1764.

He had replaced Mir Jafar with British support but later clashed with them.

He allied with Shuja-ud-Daula (Oudh) and Shah Alam II (Mughal Emperor) against the British East India Company.

The English Army in the Battle of Buxar was led by Hector Munro.