Gaeboo Achyok (r. c. 1660 – 1676)[1] orGyalpo Ajok (Tibetan:ཨ་ལྕོག,Wylie:rgyal po A lcog,THL:gyalpo achok) was aLepchachieftain of aprincipality based atDamsang, presently in theKalimpong district ofWest Bengal, India.
Achyok faced active threats from Bhutan and formed an alliance with Tibet. The conflict resulted in several wars until Achyok was captured atDaling and executed.
Achyok is aLepcha name, which is more accurately transliterated asáchúk.[2] The Tibetan spelling —Tibetan:ཨ་ལྕོག,Wylie:a lcog — can be variously transliterated as "Achuk", "Achok", "Achog", and "Ajok". Some Tibetan and Bhutanese sources also use the spelling "Amchok".[1]
Lepchas honor him withGyebú, translating to "great".[2] The Tibetans refer to him as aGyalpo, meaning "king". In contrast, the Bhutanese address him as aMonpa (low-lander), regarding him as their rebel-subject.[1]
The region consisting of present-daySikkim,Chumbi Valley and western Bhutan was largely a frontier territory since early seventeenth century.[3] Not held by any major power, its primary inhabitants were Indian tribes,Lepchas and Bhutias.[3]
In the early 17th century, Tibetans started to immigrate and settle in the region due to a variety of causes includingsectarian persecution.[3][4][5] In 1642, theroyal house of Chogyals was founded in Western Sikkim,[a] ostensibly as an alliance between Lepchas and these immigrants.[7] Around the same time, the Bhutanese state was getting unified underNgawang Namgyal and would enter into a protracted conflict with an expansionist Tibet. The first war was fought in late 1650s and the Tibetans lost comprehensively.[8][9]

The first mention of Gaeebo Achyok is found in the biography of Kunchok Gyaltshan.[10][11][c] C. 1634, Kunchok Gyaltshan, a Tibetanmonk of the Barawa sect[d] was exiled from Bhutan along with his followers for not supporting the Namgyal regime.[14]
He went on to settle in Damsang — a strategic location on a ridge overlooking theRhenock valley and theJelep La route to Tibet. Gyaltshan constructed several smallmonasteries in and around the region;[10][3] he is said to have received all necessary approvals from the Chogyals.[14]
In the meanwhile, Bhutan's religio-military assault kept on the rise with chronicles recording a dispatch of forces to nearbyDagana in 1650, to subdue recalcitrantmonpas — this might have affected Damsang, as well.[15]
Despite these hurdles, including what he notes to be an increased presence of Bhutanese monks, Gyaltshan managed to exert significant command in the local population. In 1660, he chose to return to his home monastery, in Tibet, for a vacation.[11][13]
By the time he returned c. 1663, more Lamas from Bhutan had encroached on his territories and a local Lepcha chieftain, Gaeebo Achyok, had assumed control.[11] Gyaltshan did not resist these encroachments and ventured northward.[11] The extent of Achyok's sovereignty at this stage remains uncertain.[14][e]
Soon afterward, the Bhutanese Lamas began to exert pressure on the Lepchas, aided by their regional fortress atDaling, which was probably an old Lepcha fort usurped by the Bhutanese in the war of 1650s.[11][f][g]
In 1668, Gaeboo Achyok sought assistance from His Holiness the5th Dalai Lama, and had an audience with him atLhasa. Bhutanese expansions had triggered conflicts with the Tibetans on multiple fronts. He expected a favorable response.[17]
Two months later, Tibet sent multiple columns of its army to invade Bhutan in support of Achyok, as well as a certainNyingma lama of Merak.[17][h][i]
The invasion was unsuccessful for Tibet — and for Achyok, by extension — and the troops had to be withdrawn.[17][19][j]
An armistice was called by the lamas ofTashilhunpo and other monasteries.[19]
In the post-war negotiations, both Tibet and Bhutan claimed Achyok's territory as theirs.[19] Finally, a peace treaty was signed in 1669 which called for observation of the status-quo till 1675.[21][10]
Early in 1675, Achyok informed the Tibetans that the Bhutanese were secretly preparing for an all-out offensive against him before the expiry of the peace treaty.[22][19]
While routine border incursions were commonplace,[10] this was an unprecedented development and the Dalai Lama ordered a preemptive attack, which was carried out, burning a frontier outpost at Tendung.[k]
Protracted diplomatic negotiations, including on the status of Achyok's territory, followed atPhari (var.Phag Ri), with Bhutan claiming all rights to Achyok's territory.[23]
By September 1675, His Holiness the Dalai Lama had unwillingly conceded to Bhutan's hardball tactics. However, in return, he stopped all border-trade with Bhutan.[19][23]
The stoppage of border trade appears to have fomented local rebellions which was capitalized by Achyok. In response, Bhutan launched military operations but they proved to be little effective with Achyok capturing the frontier outpost of Daling.[10][24]
Rituals were held in Punakha for the vitalization of Bhutan's forces and by the third month of 1676, the fort was taken back.
Gaeboo Achyok was captured and executed while his territories were annexed.[24] His head and arms were reportedly paraded in public after being staked in a pole.[25]
Gyalsey Tenzin Rabgye even composed a poem of compassion, deeming Achyok to have committed great evil.[25]
With a new regent at helm of affairs in Tibet, Bhutan's capture of Achyok's territories was not favorably received.[24]
War preparations were initiated, and months later, Tibet would mount the largest ever invasion of Bhutan with eleven columns of its army aiming to besiege them from all sides.[26] Tibet fared better than previous attempts but were yet again warded off.[26]
Finally, in 1679, anotherpeace deal was agreed upon and the frontiers settled.[19] Tibetan records mention nothing about this conflict or the deal.
However, the massive expansion of the Gelugpa Monastery of His Holiness the Dalai Lama came soon after, in what has been since interpreted as a deterrent to Bhutanese expansionism.[25][19][l]
Contrary to popular memory, Gaeboo Achyok was not the last Lepcha "King".[27] A successor to Achyok had emerged by 1680, called "Monpa Adzin" in Bhutanese records.[28] He seems to have not taken any side in the Tibeto-Bhutanese conflict but played off the two sides to unknown results. He partook in the negotiations over land rights in lower Chumbi Valley with the representatives of Tibet and Bhutan.[28] The Bhutanese claim that he took their side in the negotiations, which concluded after over two years in 1687.[29][m]
By 1690, Bhutanese frontier-men, if not the state, seem to have recovered Damsang for they had erected border cairns.[31]
Achyok remains a hero to the Lepchas and his birthday — allegedly on 20 December — is commemorated with much fanfare.[32]
In April 2018, both Daling Fort and Damsang Fort were enlisted as heritage sites byWest Bengal Heritage Commission.[33]