Bhotan and the story of the Doar War, by Dr. David Field Rennie. Published 1970 by Manjusri Publishing House in New Delhi, No. 695 of a limited edition of 1000 copies. The original was published in 1866 by John Murray in London, as Bhotan and the story of the Dooar War, including sketches of a three months’ residence in the Himalayas, and narrative of a visit to Bhotan in May 1865, by Surgeon Rennie, M.D., 20th Hussars.
From Wikipedia: Britain sent a peace mission to Bhutan in early 1864, in the wake of the recent conclusion of a civil war there. The dzongpon of Punakha—who had emerged victorious—had broken with the central government and set up a rival Druk Desi while the legitimate Druk Desi sought the protection of the ponlop of Paro and was later deposed. The British mission dealt alternately with the rival ponlop of Paro and the ponlop of Tongsa (the latter acted on behalf of the Druk Desi), but Bhutan rejected the peace and friendship treaty it offered. Britain declared war in November 1864. Bhutan had no regular army, and what forces existed were composed of dzong guards armed with matchlocks, bows and arrows, swords, knives, and catapults. Some of these dzong guards, carrying shields and wearing chainmail armor, engaged the well-equipped British forces. The Duar War (1864–65) lasted only five months and, despite some battlefield victories by Bhutanese forces, resulted in Bhutan's defeat, loss of part of its sovereign territory, and forced cession of formerly occupied territories. Under the terms of the Treaty of Sinchula, signed on November 11, 1865, Bhutan ceded territories in the Assam Duars and Bengal Duars, as well as the eighty-three-square-kilometer territory of Dewangiri in southeastern Bhutan, in return for an annual subsidy of 50,000 rupees.The British were constantly trying to extend and consolidate their borders in and around India and the Himalayas and access into and through Bhutan was an important goal of the Great Game. Famous in espionage annals from Rudyard Kipling’s Kim to the 2010 publication, The Horse That Leaps Through Clouds: A Tale of Espionage, the Silk Road and the Rise of Modern China by Eric Enno Tamm, the Great Game was a see-saw battle of wits, one-upmanship, secret forays and behind-the-scenes alliances to decide whether the British or the Russians would control central Asia. A foothold in Bhutan was a strategic advance for the British, who maintained cordial relations with this independent Kingdom from that date on.
A view of the current Bhutanese cavalry heading towards a border patrol