How was Punjab finally conquered?

Punjab was conquered by the East India Company when its army defeated the Sikh Empire at the battle of Gujarat on 21 February 1849. The battle ended the Second Anglo Sikh War and by 2nd April 1849, Punjab in its entirety was incorporated into the British Raj.

For further reading check the following articles:

• Second Anglo-Sikh War
• British Raj
• First Anglo-Sikh War