**The Battle of Buxar and Mir Qasim's Alliance**

The Battle of Buxar took place in 1764 between the forces of the British East India Company and the alliance of Mir Qasim, Shuja-ud-daulah, and Shah Alam II. Mir Qasim, who was the Nawab of Bengal, sought to overthrow British rule in the region and formed an alliance with Shuja-ud-daulah, the Nawab of Awadh, and Shah Alam II, the Mughal Emperor.

**Mir Qasim's Rebellion**

Mir Qasim's alliance with Shuja-ud-daulah and Shah Alam II was a result of his rebellion against the British East India Company. Mir Qasim was initially appointed as the Nawab of Bengal by the British, but he soon became dissatisfied with their interference in his administration and their oppressive policies. He led a rebellion against the British and formed an alliance with other regional powers to challenge their authority.

**Shuja-ud-daulah's Role**

Shuja-ud-daulah, the Nawab of Awadh, played a crucial role in the Battle of Buxar. He joined forces with Mir Qasim in their fight against the British East India Company. Shuja-ud-daulah had his own grievances against the British, particularly regarding the British annexation of the Allahabad and Kora territories. He saw the rebellion of Mir Qasim as an opportunity to challenge the British and regain his lost territories.

**Shah Alam II's Involvement**

Shah Alam II, the Mughal Emperor, also joined Mir Qasim's alliance in the Battle of Buxar. The Mughal Empire had been severely weakened by the invasions of Nadir Shah and later Ahmad Shah Durrani. The British had taken advantage of this weakened state and imposed their authority over the Mughal Emperor. Shah Alam II saw the rebellion of Mir Qasim and the alliance with Shuja-ud-daulah as a chance to regain his independence and challenge British dominance.

**The Outcome of the Battle**

Despite the formidable alliance formed by Mir Qasim, Shuja-ud-daulah, and Shah Alam II, the Battle of Buxar ended in a decisive victory for the British East India Company. The British forces, led by Hector Munro, were better organized and equipped, and they successfully defeated the combined forces of the alliance. The defeat of the alliance had significant consequences for the region, as it further strengthened British control over Bengal, Awadh, and other parts of India.

In conclusion, Mir Qasim formed an alliance with Shuja-ud-daulah and Shah Alam II in the Battle of Buxar to challenge British authority in the region. However, despite their efforts, the British emerged victorious, further consolidating their control over large parts of India.