From 1764, when the British position in Bengal was established beyond challenge, until 1842, when the Treaty of Nanking gave Britain the island colony of Hong Kong, the shortest route between British and Chinese territory lay across the Himalaya mountains. Until the Gurkha War of 1814–1816, the southern slopes of the Himalayas and the states that lay along them formed a narrow buffer between British territory and Tibet. As a result of the Gurkha War, British influence was brought right up to the Tibetan border, through the annexation of Kumaon in the western Himalayas, and through the establishment of a vague protectorate over the tiny hill state of Sikkim. Tibet had been evolving into a Chinese dependency since the beginning of the eighteenth century. This process, nearly complete by 1750, reached its final stage in 1792, when Tibet became, to all intents and purposes, an integral part of the Chinese Empire. The British in India were well aware of their proximity to this outpost of the power of the Chinese Emperor. In a period when British dealings with China were confined to trade at a single port, Canton, in conditions that were far from ideal, it would have been most surprising if no attempts had been made to develop Anglo-Chinese relations across the far from impassable barrier of the Himalayas.