Explanation

History

After the death of Raja Ranjit Singh in 1839 AD. 

The first Anglo-Sikh War began 

Sikhs were defeated and signed the Treaty of Lahore

In the Second Anglo-Sikh War, Load Dalhousie annexed Punjab as a British Territory

The Second Anglo-Sikh War (the first War of Sikh Independence) was a military conflict between the Sikh Empire and the British Indian Company

That took place in 1848 and 1849.