B.B.D. Bagh, formerly called Dalhousie Square, is the shortened version for Benoy-Badal-Dinesh Bagh. It is the seat of power of the state government, as well as the central business district in Kolkata in the Indian state of West Bengal.
B.B.D. stands for three young Indian independence freedom fighters — Benoy, Badal and Dinesh — who on 8 December 1930 shot dead the Inspector General of Prisons, N.S. Simpson, in the balconies of the Writers' Building of the then Dalhousie Square. The square had been named after Lord Dalhousie, Governor General of India from 1847 to 1856. At different times it has been called ‘The Green before the Fort’ or Tank Square.
The B.B.D. Bagh area is near the Hooghly River in the western part of central Kolkata and is a square built around the old Lal Dighi tank. The old fort built by the British was near where the General Post Office now is. The area was in the heart of Kalikata or the White Town in old Calcutta.
B.B.D. Bagh (or Dalhousie Square as it was formerly known) was created as the center of the British East India Company's trading post along the banks of the Hooghly River. Between the river and the tank (now known as Lal Dighi), lay the original Fort William. In the summer of 1756, Nawab Siraj ud-Daulah of Bengal, Bihar and Orissa launched an attack on the British town for the company's decision to strengthen the fortifications around it. The survivors of the attack were sent to a garrison within the fort which spurred an incident infamously known as the Black Hole of Calcutta. The British soon retook the city after the Nawab retreated from the forces of Robert Clive. Within a year, the British East India Company's forces had taken all of Bengal and Calcutta, along with the square, was established as the commercial and political center of British India.