The East India Company started as a trading company. To further its trading interest the company started to interfere in local politics and later on took control of local administration. Ultimately through various social, political and administrative changes the company took full control over 63 percent of the Indian territory and 78 percent of the population. Remaining part was under indirect control of the East India Company.

In 1600, the East India Company acquired a charter from the ruler of England, Queen Elizabeth I, granting it the sole right to trade with the East . This meant that no other trading group in England could compete  with East India company. The company did not  fear competition from other English trading companies .Mercantile trading companies in those days made Profit primarily by excluding competition , so, that they could buy cheap and sell dear .

By the first time the first  English ship sailed down the west coast of Africa , round the cape of good Hope ,and crossed the Indian , the Portuguese had already established their  presence

In western India ,and had their base in Goa .In fact , it was Vasco-da-Gama , a Portuguese explorer , who had discovered the sea route to India in 1498.                 

The first  English factory  was set near the banks of river

Hooghly in 1651 . This was the base from which the company

traders , known at that  time as the “factors”, operated .The factory  as the ware house  where the goods for export werestored, and  it offices where Company official sat. By 1696  it 

began to building forts  around the settlements . Two years later it bribed Mughal officials into the company  zamindari right over three villages. One of these was Kalikata , which grew  later Calcutta or Kolkata.         

The early  eighteenth century the conflicts between the

 company and the nawabs of Bengal intensified. After the death

of  Aurangzeb ,the Bengal nawabs  asserted  their power and autonomy as other regional power were doing that time .Murshid- Quli -khan , Alivardi khan ,Sirajuddaulah as the

nawab of Bengal . Each one of them was a strong  ruler .They

Refused to grant the company concessions, demand of large

tribute for the company’s right to trade .The company was also

Convinced that to expand trade it had  to enlarged its settlement

And buy up villages, and re building  forts .The conflicts led to the famous  Battle of Plessey 

Battle of Plassey Battle of Plassey was the most decisive war that marked the initiation of British rule in India for the next two centuries. Battle of Plassey or Palashi took place between British East India Company and Nawabs of Bengal and his French allies. The battle occurred on June 23, 1757 at Palashi of Murshidabad District, on the bank of Bhagirathi River. Murshidabad. Siraj-Ud-Daulah. The French East India Company also sent a small army to join Nawabs force against the British .The army commander Mirzafar of Siraj Ud Daulah`s side betrayed in the battle of Plassey and thereby the whole force of Nawab collapsed and as a consequence, the entire province of Bengal came under British. Thus Plassey earns its importance in Indian history as a key factor leading to the ascendance of British rule in India.

The doctrine of subsidiary alliance was introduced by Marquess Wellesley, British Governor-General in India from 1798 to 1805. Early in his governorship Wellesley adopted a policy of non-intervention in the princely states, but he later adopted the policy of forming subsidiary alliances. This policy was to play a major role in British expansion in India.