What is the meaning of the word Presidency? It means an office where the President sits and controls the area under him or her. Why did the British come up with the idea of Presidencies? The British established factories and started trade in large number of commodities. The control and administration of the factories and the people employed by the British was to be coordinated under one person. They built Fort St George in Chennai and later established the Madras Presidency in 1684.
William Gyfford became the first President. What started off as a Headquarters for administration later started controlling other areas militarily. The British started expanding their control into Mysore, Thanjavur, Vishakapattinam, etc in the South and similarly, areas around Kolkotta and Mumbai. This led to fights with the local rulers and with the established kingdoms of the Nizam, Marathas, Rajputs and the Nawab of Bengal.
The role of the Presidencies created in Kolkatta, Chennai and Mumbai were:
To have an administrative office to control the activity of trade and commerce from the ports.
To ensure the safety and security of the goods and services of the trading companies.
To build a strong army in order to expand and establish control in India.
The Company's military under Robert Clive fought many battles to establish its supremacy and control over India. The main battles fought were the 1757 Battle of Plassey, the 1764 Battle of Buxar (in Bihar) and The Company thus became the de facto ruler of large areas of the lower Gangetic plains by 1773.
It also proceeded slowly to expand its dominions around Bombay and Madras. The Anglo-Mysore Wars (1766-99) and the Anglo-Maratha Wars (1772-1818) ensured its control of large areas of India south of the Sutlej River.
Establish a civil-military rule in India.
The famous quote that "the Sun never sets in British Empire" which indicates the expansion of the British Colonies across the Globe. Wherever the British conquered countries they became permanent settlers. Thus, the three Presidencies of Madras, Bengal and Bombay were created both as administrative as well as military centers.
Having created the Presidencies the East India Company made an organization, in each of these locations, to rule the areas, which were annexed by them. The Presidencies had one Governor who was the head and assisted by a council of four members. This included one Commander-in-chief of the Army. Each of these presidencies had its own army and was called Bengal Presidency (the Bengal Army), Madras Presidency (the Madras Army) and Bombay Presidency (the Bombay Army). They had regular regiments of British soldiers and officers.
Slowly the Company started recruiting Indian natives to serve as sepoys in these armies.