Battle of Plassey 1757: causes, betrayal and why it began British rule

Bengal on the eve of the battle

By the mid-eighteenth century the Mughal Empire was in decline, and Bengal, one of its richest provinces, had become effectively independent under its nawabs, with its capital at Murshidabad. The British East India Company, chartered in 1600 for trade in the East Indies, had grown into a military presence of its own, with a strong garrison at Fort William in Calcutta and factories across Bengal.

The new Nawab, Siraj-ud-Daulah, who succeeded his grandfather Alivardi Khan in 1756, was suspicious of the Company's growing power. He objected to its misuse of duty-free trade passes, which cut into his customs revenue, to its fortification of Calcutta without his permission, and to its shelter for Krishna Das, a fugitive accused of taking state funds. The two sides were also caught up in the wider Anglo-French rivalry of the Seven Years' War, and Siraj-ud-Daulah leaned towards the French.

Calcutta, the Black Hole and the road to Palashi

In 1756 Siraj-ud-Daulah marched on Calcutta and captured Fort William. In the aftermath, 146 British prisoners were confined overnight in a small, cramped room, and according to one prisoner's account 123 of them died of suffocation and dehydration. The episode, remembered as the Black Hole of Calcutta, became the Company's justification for revenge, although modern historians treat the traditional figures with caution.

Robert Clive was sent from Madras with reinforcements, retook Calcutta by February 1757 and captured the French fort at Chandernagore in March. Meanwhile Clive and the Jagat Seth bankers were quietly negotiating with disaffected men inside the Nawab's court, above all Mir Jafar, who was promised the throne if he abandoned his master. By June the armies were facing each other near the village of Palashi, on the road to Murshidabad.

A battle decided by rain and betrayal

The fighting itself was brief and one-sided. After an opening exchange of artillery fire, a heavy downpour soaked the battlefield. The British covered their gunpowder with tarpaulins, but the Nawab's gunners did not, and their powder was ruined. Believing the British guns to be equally useless, the Nawab ordered a cavalry charge that ran into a devastating artillery barrage.

At the decisive moment Mir Jafar refused to commit his troops, leaving a flank exposed, and the Nawab's remaining positions were bombarded without reply until his army broke. Siraj-ud-Daulah fled the field but was captured by men loyal to Mir Jafar and later executed. British losses were put at 22 killed and 50 wounded, against about 500 killed on the Nawab's side, figures that show how little real fighting took place once the conspiracy took effect. Loyal officers such as Mir Madan and Mohan Lal were among the few who resisted to the end.

Why Plassey changed Indian history

The consequences were out of all proportion to the battle. Mir Jafar was installed as Nawab, but he was a puppet: through a series of treaties he ceded effective control of Bengal to the Company, and when he tried to escape British control by intriguing with the Dutch, he was replaced. The Company then used Bengal's revenues to pay for its armies and its trade, financing further conquests across India.

Plassey is therefore remembered less as a military victory than as a political one. It converted a commercial company into a territorial ruler, gave Britain the richest province in India as a base, and set the pattern for the expansion that followed, through Buxar in 1764, Mysore in 1799 and Punjab in 1849, until the Company, and then the Crown, ruled the subcontinent. For that reason textbooks often call 23 June 1757 the beginning of British rule in India, even though formal empire came much later.

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