1757
Battle of Plassey
The setting
Palashi, on the Bhagirathi river north of Calcutta, in modern West Bengal
Mango grove beside a river, monsoon ground. A downpour mid-battle soaked the Nawab's powder while the Company covered its own.
Read the historical account
Company victory, secured before the fighting by agreement rather than during it by arms.
It was not really won on the field. Clive had already contracted with Mir Jafar, commanding a large part of the Nawab's army, to stand still - and he did. Roughly two-thirds of Siraj's force never engaged. The monsoon downpour that ruined the Bengali powder and spared the Company's, and the death of the one loyal general, Mir Madan, did the rest. The casualty figures are the tell: 22 dead does not describe a battle.
What followed
The beginning of British territorial rule in India. A trading company acquired the revenues of Bengal, and with them the means to conquer the rest. ⚠ It is also the atlas's sharpest case of an engagement that is remembered as a battle and was substantially a transaction - the commander idiom fits it poorly, and that is stated rather than smoothed over.