British India, before and during the time of the prolonged British Raj, possessed three presidencies, autonomous in their respective domain.
They comprised:
Bengal Presidency (Presidency of Fort William)
Bombay Presidency
Madras Presidency (precisely, the Presidency of Fort St. George)

India during the extensive period of British rule was an extraordinary amalgamation and mish-mash of cultural unification and pitiless over-domination. Beginning from East India Company ruling, when the country was basically looked as the eastern magical land of spices and brocades, and culminating in the strict regime of Queen Victoria, British India was administered by different modes. For example, the policy of `Divide and Rule` was one such tremendous hindrance to native populace, as compared to equality in the career concerning Civil Services. With India being a colossal country, redefining its boundaries, English rulers had made it a systematic policy to classify the country by the basis of village, town and city. Since a long time, the major port cities like Calcutta, Madras and Bombay had assumed momentous importance owing to their accessibility with other regions beyond the country. These three cities had thus witnessed an overwhelming presence of English population, making it their permanent domicile. As such, trading and commerce boomed towards elevating heights, with working output adding up to both native and `white` workers. In this regard, Calcutta, Bombay and Madras were declared Presidency towns under British Indian rule. Presidencies during British India possessed an enormous periphery-line, with the erstwhile princely states being included within them.
The Presidencies in British India had primarily descended from the sagging Mughal Empire and had as such, been towing in the line of ancient Indian sovereignty. Such `old` ideas were completely done away with, as the presidency towns started to be governed in a rather western stylisation of reign. Voyages to and from England, since the 17th century was a regular feature in Bombay, Calcutta or Madras, with English settlers absolutely realising the art of how to invade and capture territories for augmented growth.
These Presidencies during British India out-and-out reflected the prototype of establishment of British trading factories and forts in and around 17th and 18th centuries. The first trading post of Surat, was founded during early seventeenth century, only later to be deserted for brighter purposes. This monumental event was succeeded by settlements on the Coromandel coast, of which Madras seized prominence and was henceforth named the `Madras Presidency`. The trading post in Bengal, headquartered in Calcutta became the focal point of the `Bengal Presidency`, the seat of the Governor-General of India, who reigned over the East India Company`s Indian ownerships. The island of Bombay which was triumphantly gained as part of dowry in a royal union turned out the centre of operations for the Konkan coast and the heart of the `Bombay Presidency`. Each of the Presidencies additionally possessed their respective Presidency armies, as was known from Bengal Army, Madras Army and Bombay Army.