Analysis of information sources in references of the Wikipedia article "Anglo-Manipur War" in English language version.
After comprehensively defeating the Burmese in 1826 in Assam and Manipur, and the signing of the Treaty of Yandabo, the British annexed Assam, but allowed Manipur to remain a protectorate state.
The British authorities felt that Manipur would hardly stand independently without their 'benevolent' help. Gradually, they began to take Manipur as a protectorate state.
Legally, however, Manipur never acknowledged the suzerainty of the British Government.
Manipur then became a British protectorate although final annexation was only to take place in 1891.
As Captain Drury had only 100 rifles of the 2-4th Gurkha Regiment, 50 rifles of the 12th (Burma) Madras Infantry, and 44 mounted infantry of the 12th (Burma) Madras Infantry with him, and as I did not think this force strong: enough for the purpose, I ordered two guns of No. 2 Mountain Battery and 200 rifles of the 2-4th Gurkha Regiment, the whole under the com- mand of Captain Rundall, 2-4th Gurkha Regi- ment, to reinforce Captain Drury. Captain Rundall, on arrival at the scene of action, placed his guns on a hill about 1,000 yards from the entrenchment, and commenced to shell it.