[1] Official documents always cited cross-border raids by Bhutan or sheltering of dissidents as the immediate cause; however, modern historians note Britain's imperialist ambitions in the region to be the actual pretext.

[1] Not only was Bhutan a vital cog in the Indo-Tibetan trade but also the commercial viability of Duars region for supporting tea plantations was well known among Company officials.

Bhutan had no regular army, and what forces existed were composed of dzong guards armed with matchlocks, bows and arrows, swords, knives, and catapults.

The British initially suffered a humiliating defeat at Deothang and when they recaptured Dewangiri they dismantled the fortress there to deny its use to Bhutanese forces.

[5] On the 11th day of November, 1865 Treaty between His Excellency the Right Honourable Sir John Lawrence, G.C.B., K.S.I., Viceroy and Governor-General of Her Britannic Majesty's possessions in the East Indies, and the one part by Lieutenant Colonel Herbert Bruce, CB, by virtue of full powers to that effect vested in him by the Viceroy and Governor – General, and on the other part by Samdojey Deb Jimpey and Themseyrensey Donai according to full powers conferred on them by the Dhum and Deb Rajahs, 1865.