Battle of Plassey was fought on 23 June 1757 between the forces of the British East India Company and the army of Siraj-ud-Daula, the Nawab of Bengal. The British East India Company, led by Robert Clive, emerged victorious in the battle. Here is how the company official won the battle of Plassey:

Preparation:
- The British East India Company had formed an alliance with Mir Jafar, one of Siraj-ud-Daula's commanders, who had promised to support them in the battle.
- Robert Clive had also trained his troops and equipped them with modern weapons, including artillery.

Strategic moves:
- The British forces strategically placed their troops and artillery in a way that made it difficult for Siraj-ud-Daula's army to attack them.
- When Siraj-ud-Daula's army attacked, the British forces responded with a barrage of artillery and gunfire.
- The betrayal of Mir Jafar and his forces turning against Siraj-ud-Daula's army also played a significant role in the outcome of the battle.

Leadership:
- Robert Clive's leadership skills were crucial in the victory; he rallied his troops and made quick decisions on the battlefield.
- Siraj-ud-Daula's leadership was weak, and he failed to make strategic decisions during the battle.

Aftermath:
- The victory at the Battle of Plassey gave the British East India Company control over Bengal, which was a significant trading center in India.
- The Company was now able to establish its power and influence in India, leading to further expansion and colonization of Indian territories.

In conclusion, the British East India Company's preparation, strategic moves, and leadership, along with the betrayal of Mir Jafar, were the key factors that led to their victory in the Battle of Plassey.

The company used Siraj ud daullah's deposed army chief Mir Jafar against Siraj ud daullah's and defeat him in the Battle of Plassey.