The British gained power in Bengal through a series of strategic actions and political maneuvers during the 18th century. Their control over Bengal was a significant milestone in the expansion of the British Empire in India.

- Establishment of the East India Company: The British East India Company was initially granted a trading license by the Mughal Emperor in the early 17th century. Over time, the Company established trading posts and gained economic influence in Bengal.
- Battle of Plassey (1757): One of the pivotal events in the British conquest of Bengal was the Battle of Plassey. The British, led by Robert Clive, defeated the forces of the Nawab of Bengal, Siraj-ud-Daulah. This victory allowed the British to establish their dominance in Bengal.
- Treaty of Allahabad (1765): Following the Battle of Buxar, the British East India Company signed the Treaty of Allahabad with the Mughal Emperor Shah Alam II. This treaty granted the Company the diwani rights of Bengal, Bihar, and Orissa, giving them control over the economic and administrative affairs of these regions.
- Consolidation of Power: The British gradually consolidated their control over Bengal by exploiting internal divisions among the local rulers, establishing a system of indirect rule, and implementing administrative reforms.

In conclusion, the British gained power in Bengal through a combination of military victories, diplomatic agreements, and economic exploitation. Their control over Bengal laid the foundation for the expansion of British colonial rule in India and significantly influenced the course of Indian history.