British relations with Punjab evolved from cautious diplomacy to outright conquest during the first half of the 19th century. Initially, the British viewed Maharaja Ranjit Singh’s Sikh kingdom as a useful buffer against a possible French invasion through the North-West. This policy culminated in the Treaty of Amritsar (1809), signed between Ranjit Singh and the East India Company, which fixed the Sutlej river as the boundary between Sikh and British territories. While the treaty checked Sikh expansion east of the Sutlej, it allowed Ranjit Singh to consolidate power westwards, including Kashmir and Peshawar, ensuring a period of uneasy friendship.

The situation changed dramatically after Ranjit Singh’s death in 1839. Punjab plunged into political instability marked by weak rulers, court intrigues, and the growing indiscipline of the Khalsa army. The British closely monitored these developments, especially after their prestige suffered in the Afghan War. The annexation of Sindh in 1843 and military preparations along the Sutlej heightened Sikh suspicions and led to armed conflict.

The First Anglo-Sikh War (1845–46) ended with the Sikh defeat at Sobraon and the Treaty of Lahore, which reduced Punjab to a British dependency and transferred Kashmir to Gulab Singh. Continued interference led to the Treaty of Bhairowal, which made the British Resident the real authority in Punjab. Persistent unrest culminated in the Second Anglo-Sikh War (1848–49). After the decisive Battle of Gujarat, Lord Dalhousie annexed Punjab in 1849. Maharaja Duleep Singh (also spelt Dalip Singh) was deposed, the Koh-i-Noor was seized, and Punjab was brought under direct British administration, ending Sikh sovereignty.