Anglo-Bhutanese Relations under British Rule

British relations with Bhutan began in the late 18th century as the British East India Company expanded into Bengal and Cooch Behar. In 1770, Bhutan invaded Cooch Behar, a kingdom bordering Bengal. Cooch Behar sought British protection, prompting Governor-General Warren Hastings to send troops in 1772 to drive the Bhutanese back into the hills. The conflict ended with the Treaty of 1774. The Panchen Lama of Tibet mediated between the two parties. Bhutan agreed to return to its pre-1770 borders and pay a tribute of five horses to the Company. In return, Warren Hastings restored captured territories to Bhutan and attempted to open commercial trade routes through Bhutan into Tibet.

The Duars Question and Frontier Tensions

The annexations of Assam (1826) and Lower Burma (1852) extended British frontiers directly up to Bhutan’s southern borders. Friction centered on the fertile Duars—lowland passes leading from the Himalayan foothills into Bengal and Assam.

The Bengal and Assam Duars

The Duars were divided into two main sectors: the 7 Assam Duars and the 11 Bengal Duars. The Assam Duars were originally under joint management, where Bhutan paid annual tribute to local rulers, a practice the East India Company inherited. Bhutanese officials often defaulted on tribute payments and conducted cross-border raids into British territories to collect revenue and captives. The British annexed the 7 Assam Duars between 1841 and 1842, agreeing to pay Bhutan an annual compensation of 10,000 rupees. However, disputes over the 11 Bengal Duars persisted, leading to deteriorating relations throughout the mid-19th century.

Mission of Ashley Eden and Outbreak of War

In 1863, the British sent a diplomatic mission led by Ashley Eden to Punakha to settle boundary disputes, stop raids, and secure a formal treaty.

The Eden Mission (1863–1864)

The Bhutanese Durbar, experiencing internal power struggles between rival governors (Penlops), treated Ashley Eden with hostility. The Penlop of Tongsa forced Eden to sign a favorable treaty ceding control of the Assam Duars to Bhutan and surrendering runaway captives. Upon returning to Calcutta, Eden repudiated the agreement, and Viceroy Lord Lawrence declared war on Bhutan in November 1864.

The Duar War and Treaty of Sinchula (1865)

The Anglo-Bhutanese War, also known as the Duar War (1864–1865), was fought along the Himalayan foothills. British forces faced initial setbacks at Dewangiri but used superior artillery to capture key passes and forts.

The Treaty of Sinchula (1865)

Signed on November 11, 1865, the Treaty of Sinchula established peaceful relations and defined the southern border of Bhutan.

The annexation of Kalimpong gave the British control over crucial trade corridors leading through the Chumbi Valley toward Lhasa.

Treaty of Punakha (1910) and Monarchy Establishment

In 1907, Ugyen Wangchuck, the Penlop of Tongsa who had assisted Francis Younghusband’s 1904 expedition to Lhasa, was elected as the first hereditary King (Gyelpo) of Bhutan. This centralized the Bhutanese political system. To counter growing Qing Chinese influence in Tibet and prevent foreign interference along the northern frontier, Viceroy Lord Minto revised relations with Bhutan. On January 8, 1910, political officer Charles Bell negotiated the Treaty of Punakha with King Ugyen Wangchuck.

Key Outcomes of the 1910 Treaty

• Foreign Policy Control: Bhutan agreed to guided foreign relations, placing its external affairs under the advice of the British Indian government.
• Non-Interference: The British promised strict non-interference in Bhutan’s internal administration.
• Increased Subsidy: The annual British subsidy to Bhutan doubled from 50,000 rupees to 100,000 rupees.

Key Historical Facts

George Bogle was dispatched by Warren Hastings in 1774 as the first British envoy to Bhutan and Tibet, followed by Samuel Turner in 1783 and Robert Boileau Pemberton in 1837. The term Duar means “door” or “gateway,” referring to the 18 mountain passes that connect the plains of Bengal and Assam with the Himalayan kingdom of Bhutan. The Treaty of Sinchula (1865) turned Bhutan into a friendly buffer state between British India and Tibet, securing the northeastern frontier without requiring direct military occupation or annexation of the hills. The 1910 Treaty of Punakha laid the foundation for post-independence relations. India and Bhutan signed the Indo-Bhutan Treaty of Friendship in Darjeeling on August 8, 1949, which retained the core provisions of the 1910 treaty regarding external affairs and free trade.