Battle of Plassey to Annexation of Punjab in 1849. They used several methods apart from war, like the Subsidiary Alliance and the doctrine of Lapse to expand and consolidate their rule in India.
Conquest of Bengal
In 1717, the East India company got Farman from Mughal emperor Farrukh Siyar. This Farman Granted English East India Company, the freedom to export and import without paying tax in Bengal.
This Farman created a huge loss of revenue for the Nawab of Bengal and created conflicts with the East India Company.
This Royal Farman also gave East India Company other rights such as levying Heavy taxes on Indian Goods entering Calcutta (Bengal).
Also, the East India Company built Fortification, which created a rivalry between Nawab of Bengal and the East India Company.
The East India Company planned to overthrow the Nawab of Bengal, Siraj-ud-Daulla by joining hands with several members inside the Nawabs court.
Example: Mir Jafar, Mir Bakshi, Manik Chand (officer in charge of Calcutta), Amir Chand (Big Banker in Bengal), and Khadim Khan (One of Commander in Nawab in Bengal).
Battle of Plassey (1757)
Nawab of Bengal and East India Company fought in the Battle of Plassey. Mir Jafar and Rai Durlabh took no part in the fighting and left the battlefield.
Nawab Siraj-ud-Daulla was captured and killed. Mir Jafar was made Nawab of Bengal. Then Mir Jafar was deposed in 1760, as he did not fulfil the demands of English.
Then Mir Qasim, son-in-law of Mir Jafar was made Nawab of Bengal.
Battle of Buxar (1764)
Mir Qasim too was not loyal to the East India Company. War broke out between East India Company and Mir Qasim.
Mir Qasim went to Awadh and formed an alliance with Nawab of Awadh, Shuja-ud-Daula, and Mughal Emperor Shah Alam. This alliance fought together against the East India Company in1764 at Buxar.
East India Company won the battle of Buxar. The treaty of Allahabad was signed between the Mughal emperor Shah Alam-II and Rober Clive of East India Company, as a result of the Battle of Buxar on 22 October 1764.
Based on this East India Company was granted Diwani Rights. Diwani rights is the right to collect revenue in Bengal, Bihar, and Orissa. This victory gave East India Company as political masters of Bengal, Bihar, and Orissa.
Next to English East India company turned toward Mysore state. Already there was a rivalry between Mysore, Nizam of Hyderabad, and Marathas.
This rivalry gave the English an opportunity to interfere and expand their political dominance. This rivalry resulted in four wars between the East India Company and the Mysore state called as Anglo Mysore Wars.
First Anglo-Mysore War (1767-69)
Haider Ali got some success against the British.
Second Anglo Mysore War(1780-1784)
Proved indecisive, ended with the treaty of Mangalore.
Third Anglo Mysore War(1789-1792)
Tipu Sultan invaded Travancore, which is an English Ally. Tipu Sultan was defeated in the Third Mysore War, forcing him to sign the Treaty of Seringapatam.
According to the treaty, Tipu had to surrender half of his kingdom to the East India Company and to its allies.
Fourth Anglo Mysore War(1799)
British Defeated Tipu Sultan. Tipu died while defending the capital. Half of Mysore Territory was divided between the British and Nizam
Conquest of Marathas
The conquest of the Maratha Empire was called as Anglo-Maratha War.
First Anglo Maratha War (1775-1782)
British were defeated and the Treaty of Salbai was signed.
British Won Second Anglo-Maratha War (1803-1806) and the third Anglo-Maratha war (1817-1818).
The reason for Maratha’s defeat is a mutual conflict between the Marathas chiefs.
The annexation of Awadh (1856)
Awadh was annexed to the English East India Company on the basis of ‘Misgovernance‘. English accused Nawab of Awadh, Wajid Ali Shah of Misgovernance.
Awadh was annexed by Lord Dalhousie in 1856. Nawab of Awadh, Wajid Ali Shah was the only ruler to be deposed on basis of ‘Misgovernance‘.
Sind Conquest (1843)
Since the 18th century, Sindh was being ruled by some Baluchi Chiefs collectively known as “Amir of Sind”.
General Charles Napier captured the Sindh province in 1843 through the battle of Miani.
With the Death of Ranjith Singh in 1839, the Conquest of Punjab was completed in 1849. There was two war fought between Sikhs and the English.
First Anglo-Sikh War (1845-1846)
British defeated Sikh troops and the treaty of Lahore was signed. To take revenge for the first Anglo-Sikh war, Sikhs created a number of revolts that lead to the second Anglo-Sikh war.
Sikhs were defeated, whole Punjab went under British Control. By this the conquest of India is complete.
The British were able to expand and consolidate their rule of India, main because India was not united. They were divided mainly based on religion, caste, linguistics, etc. The English signed several treaties, and military and trade alliances with many small, large, and independent states.
Also the British were very effective at infiltrating their internal affairs and gradually took control over the entire Indian subcontinent.