Murshid Quli Khan was the Diwan of Bengal during the reign of Aurangzeb in Delhi. He later on asserted his independence. The battle of Plassey was fought between the English and the then Nawab of Bengal in 1757 AD. In this battle the Nawab of Bengal was badly defeated, and this laid the foundation of British empire in India.
The deposed Nawab of Bengal Mir Qasim wanted to regain his lost Nawabi, so he formed an alliance with Shuja-ud-Daula (the Nawab of Avadh) and the Mughal emperor Shah Alam. The three Indian Monarchs fought a decisive battle of Buxar in 1764 AD with the forces of the East India Company. They were badly defeated. Shuja-ud-Daula and Shah Alam submitted and war came to an end. The war of Buxar in 1764 AD, laid the foundation of British empire in the whole of northern India.
The English fought four wars against Hyder Ali of Mysore and his son Tipu Sultan in south India, which are known as Mysore was in Indian history. The fourth and the last Mysore war was fought between the English and Tipu’ Sultan in 1799 AD. In this war Tipu war defeats and he died fighting bravely. After the death of Tipu Sultan the Mysore was annexed to the British Empire. In the same manner the English fought four wars against the Marathas which are known as the Maratha war in the history of India. After the end of the fourth and the last Maratha war all the territories of the Maratha was annexed by the English.
After the death of Maharaja Ranjit Singh, the English fought two wars against the Sikhs. The second and the last Sikh was fought in 1848 AD. The Sikhs were defeated and the Punjab was annexed to the British empire in 1849 AD. In this way almost the whole country came under the British Empire.