The Battle of Plassey (1757) was fought between the East India Company and:

The Battle of Plassey was fought on 23 June 1757 at Palashi, on the banks of the river Bhagirathi, in the Nadia district of present-day West Bengal. The East India Company's forces, led by Robert Clive, defeated Siraj-ud-Daulah, the Nawab of Bengal.

Siraj-ud-Daulah became the Nawab of Bengal in 1756, after the death of his grandfather, Alivardi Khan. He was unhappy with the Company's misuse of trade privileges and its fortification of Calcutta without permission. In 1756, he captured Fort William in Calcutta. The British prisoners were held in a small room, and many are said to have died; the British called this the "Black Hole of Calcutta", although the numbers have been disputed by historians. Clive was sent from Madras, recaptured Calcutta, and plotted with the Nawab's discontented officials.

Although the Nawab's army was much larger, the battle was decided by betrayal. Mir Jafar, the commander of the Nawab's army, had made a secret agreement with Clive and did not fight. Other conspirators included the banker Jagat Seth, Rai Durlabh and Omichand. Siraj-ud-Daulah was defeated, captured and killed, and Mir Jafar was made the new Nawab.

The Battle of Plassey is regarded as the beginning of British political rule in India. The Company gained enormous wealth and the right to trade freely in Bengal, and it became the real power behind the Nawab. Mir Jafar was later replaced by Mir Qasim, which led to the Battle of Buxar in 1764. The Mughal emperor at the time of Plassey was Alamgir II.

Why not the other options?

• ✗Mir Qasim fought the British at the Battle of Buxar (1764).
• ✗Shuja-ud-Daula, the Nawab of Awadh, also fought at Buxar.
• ✗Tipu Sultan of Mysore fought the British in the Anglo-Mysore wars.