The Black Hole of Calcutta was a small dungeon in the old Fort William at Calcutta, India, where troops of the Nawab of Bengal, Siraj Ud-Daullah, held the British prisoners of war after the capture of the Fort on June 19, 1756. Nearly four days of fighting insued, with many British casualities. The prisoners were initially treated well, but after some of them attacked the Nawab's guards, they were confined in a guard room and locked up overnight. This room would become the infamous Black Hole of Calcutta. Accounts differ on whether the Nawab himself or its soldiers initiated the imprisonment.
Fort William was established to protect the East India Company's trade in the city of Calcutta, its principal Presidency Town of the Bengal Presidency. In 1756, with a view to the possibility of conflict with French forces, the British began building up the fort's military strength and defences. The Nawab of Bengal, Siraj Ud-Daulah, was unhappy with company's interference in the internal affairs of his province and perceived a threat to its independence.He ordered an immediate stop to the Fort's military enhancement, but the company paid no heed . As a consequence, Siraj organised his army and laid seize to the Fort, whose defenders took many casualities. The Garrison's commander organised an escape and left a token force in the Fort under the command of John Zephaniah Holwell, a one-time military surgeon who was a senior East India Company civil servant. However, desertions by allied troops, mainly, Dutch, made even this temporay defence untenable, and the fort was taken.
The Black Hole of Calcutta, was a 14 by 18 ft room with two small barred windows. The night was hot and there was no water in the room. The guards did provide some water when the prisoners begged for it. According to Holwell's account, some prisoners were akready dead by 9 p.m. and the room was not opened until 6.00 a.m., the next morning.Out of 146 prisoners allegedly confined in the Black Hole of Calcutta, only 23 survived.
Experiments have tested whether the alleged amount of people confined in the Black Hole could have actually physically fit into a space of those dimensions. Bengal land lord Bholanath Chunder found that much less than 146 of his tenants could fit into a 15 by 18 ft area and Bengal villagers are on average smaller than English soldiers. Holwell's figures would have left each prisoner with only 1.8 sq.ft. A 50 ft. obelisk was erected on the site of the trajedy in honour of the victims , but it was removed to the nearby St. John cemetery in 1940, as Indian nationalists, under the leadership of Subhas Chandra Bose found its implications offensive.