Dalhousie Square was once the center of mercantile and political power that made Calcutta the grandest city city ever built by the Europeans outside Europe. Armenian, Chinese, Jewish and Scots businessmen set shop here to participate in the three-way trade between Britain, China and India. Dalhousie Square was the cradle of such veritable international institutions as Standard Chartered Bank (formerly The Chartered Bank of India, China & Australia) and P & O Shipping (which acquired the Calcutta-based British India Steam Navigation Company to become the world's largest, and most celebrated shipping company). Dalhousie Square was home to trading houses that were part responsible for the Opium Wars in China, since most of the opium sold in China came from Bengal. Dalhousie Square was home to the railway companies that soon spread out in every possible direction from Calcutta and built what is today the largest railway system in the world. Its businesses inspired the first international airlines to fly to Calcutta (in the 1930s, KLM flew from Amsterdam to Batavia, now Jakarta, Air Orient flew Paris to Saigon and Imperial Airways flew from London to Hong Kong/Singapore, all via Calcutta, the Chinese national airlines, China National Aviation Company was headquartered for a while in Calcutta, and in 1947, when Pan Am introduced the first round the world flight, they called it "New York to San Francisco via Calcutta" even though the flight touched over two dozen destinations around the world). Today Dalhousie Square is still the nerve center of Calcutta's business world. While labor unrest in the 1960s and 1970s caused many companies to wind up their operations from Calcutta, investors stayed on in the city, making Calcutta Stock Exchange the only profitable securities trading center in India that is not located in Bombay, the financial capital. Many of these companies have given Dalhousie Square an architectural gem in the form of their headquarters, which has directly contributed to Calcutta having more Victorian architecture today than all of London. Dalhousie Square is today listed as a heritage site by the World Monuments Fund.

We start our tour of Dalhousie Square at the Chandni Chowk Metro station (junction of Chittaranjan Avenue and Mission Row) at about 9:00 a.m. This is the beginning of the morning rush, when thousands of commuters spill into the streets of Dalhousie Square making their way to work like busy ants. The British did not start working until late in the morning in India, which is why core business hours are 10:00 a.m. to 4:00 p.m. It is possible to visit Dalhousie Square outside these hours, of course, but it being almost exclusively a business district, the area is almost deserted outside of business hours. Follow the crowd (you do not have much of a choice otherwise) west along Mission Row (officially renamed Ganesh Chandra Avenue), passing the Old Mission Church, built in 1770 by Swedish missionaries and the oldest Protestant place of worship in existence in Calcutta. Continue along Mission Row until you reach the junction with Bentinck Street. Bentinck Street, which runs south from here to Esplanade, is still home to a large number of Chinese shoemaker establishments. The shoes are made in the finest of western traditions by Chinese businesses in India, and right about sums up the cosmopolitan nature of Calcutta. Continuing along Mission Row, you walk under the shadows of lofty buildings, many of which are grimy today, much like midtown Manhattan, but you can feel their  importance as you walk along. One of them is Nilhat House, built by someone who made a fortune in indigo (Nil is Bengali for indigo) and today a center of tea auctions (Calcutta is the largest tea auction center in the world - all of London's famous tea companies - Lipton, Twinings, Harrod's, to name a few, buy their finest Assam and Darjeeling teas here, while the parent company of Tetley is headquartered in Calcutta). One more block along Mission Row and you arrive at the southeastern corner of Dalhousie Square, the oldest district of the city of Calcutta. It started as Tank Square, until it was renamed in honor of Lord Dalhousie, Governor-General until 1856, who upset the applecart by his indifference to Indian cultural and religious traditions and sparking the First War of Independence (Sepoy Mutiny) of 1857, which led to the demise of the East India Company and eventually of the British empire, 90 years later. Dalhousie Square was officially renamed Benoy Badal Dinesh Bag (BBD Bag) after three militant freedom fighters  who carried out a terrorist attack on the seat of the Bengal government in the 1930s, but were either shot or committed suicide.