Commodore's broad pennant, British India Steam Navigation Company, London. A white burgee bearing a red saltire and a red ball at the hoist. The flag is made of a wool and synthetic fibre bunting. It has a cotton hoist and is machine sewn. A rope and two Inglefield clips is attached.

The company was set up in 1856 by a Scottish firm of general merchants, Mackinnon, Mackenzie & Co., as the Calcutta and Burmah Steam Navigation Company to run a mail service between Rangoon and Calcutta. A new company was founded called the British India Steam Navigation Co. Ltd in 1862 to run services from Calcutta and Bombay to Indian Ocean ports, using local coal and with a subsidy from the government of Bombay. With the opening of the Suez Canal in 1869, BI began direct services between India and the UK, their routes eventually extending to East Africa, the Far East and Australasia.

BI ships were used for trooping in most conflicts until the British Government changed over to air transport in 1960. In 1893, the original company chairman Sir William Mackinnon died. In 1914 BI amalgamated with P&O. The company suffered a loss of business as a result of Indian independence in 1947. It lost its separate identity with the reorganisation of P&O in 1971.