The Battle of Plassey was a significant win of the British East India Company over the Nawab of Bengal and his French forces on June 23, 1757, led by Robert Clive, and made possible by the defection of Mir Jafar, the commander in chief of Nawab Siraj-ud-Daulah. As a consequence of the struggle, the Company was ready to capture the authority of Bengal. They took possession of almost all of the Indian subcontinent, Myanmar, and Afghanistan during the following 100 years.

Palashi, on the banks of the Hooghly River, roughly 150 kilometers north of Calcutta and south of Murshidabad in West Bengal, was the site of the fight (now in Nadia district in West Bengal). The British East India Company and Bengal's last autonomous Nawab, Siraj-ud-Daulah, conflicted. He was Alivardi Khan's successor (his maternal grandfather). The year previously, Siraj-ud-Daulah became the Nawab of Bengal, and he had instructed the English to halt expanding their fortifications. Robert Clive bribed Mir Jafar, the Nawab's army commander-in-chief, and promised to appoint him Nawab of Bengal. In 1757, Clive defeated Siraj-ud-Daulah at Plassey and took Calcutta.

The fight was preceded by Nawab Siraj-ud-invasion Daulah's on British-controlled Calcutta and the Black Hole massacre. Colonel Robert Clive and Admiral Charles Watson led forces from Madras to Bengal and regained Calcutta. Clive then took the initiative to take Chandannagar, a French fort. The Battle of Plassey was the culmination of tensions and distrust between Siraj-ud-daulah and the British. The combat took place during the Seven Years' War, when the French East India Company dispatched a small army to fight against the British, mirroring their European rivalry. Siraj-ud-Daulah made his stand at Plassey with a significantly superior numerical army.

Concerned about being outmanned, the British developed a plot with Siraj-ud-degraded Daulah's army leader Mir Jafar, as well as others including Yar Lutuf Khan, Jagat Seths, Umichand, and Rai Durlabh. Mir Jafar, Rai Durlabh, and Yar Lutuf Khan gathered their forces near the battleground but did not engage in combat. Due to Siraj-ud-departure Daulah's from the battlefield and the conspirators' inaction, Col. Robert Clive's 3,000 men beat Siraj-ud-army Daulah's of 50,000 soldiers, 40 cannons, and 10 war elephants. In total, the combat lasted around 11 hours.

This is considered one of the important conflicts in the colonial powers' dominance of the Indian subcontinent. The British now had considerable clout with the Nawab, Mir Jafar, and were able to extract major concessions in exchange for prior trade losses and revenue. The British used this money to bolster their troops and drive out other European colonial rules, like the Dutch and the French, from South Asia, extending the British Empire.