The name ‘Darjeeling’ is thought to be originated from the Tibetan words, ’dorje’ meaning thunderbolt (originally the sceptre of Lord Indra) and ‘ling’ a place or land, hence ‘the land of the thunderbolt’.

Originally Darjeeling was inhabited by the 'Lepchas', 'Limbus' and 'Bhutias' as part of Sikkim and in 1642, Phuntsog Namgyal became the first Chogyal (King) of Sikkim. The Gorkha army from Nepal invaded Darjeeling during 1780s, attacked the Sikkimese capital of Rabdentse and annexed territories up to Teesta river into Nepal.

After the Anglo-Gorkha war, Nepal ceded one-third of its territories to the British as per the Treaty of Sugauli in 1815, which included the land area between the rivers Mechi and Teesta. In 1817, the British reinstated the land area between Mechi and Teesta to the Sikkimese Chogyal as per Treaty of Titalia.

In subsequent years, disputes between Nepal and Sikkim came up regarding their border and during 1829 the British Governor General sent two officers Captain George Alymer Lloyd and Mr J. W. Grant to help resolve the dispute. During their brief stay of 6 days at ‘the old Gorkha station called Dorjeling’, the officers were so impressed with natural beauty of the place that Lloyd suggested government regarding the possibility of developing Darjeeling as a sanatorium. Lloyd also emphasised the need to develop and take control of Darjeeling considering advantage that Britishers would have as it served strategically in commanding entrance to Nepal and Bhutan, serving as a British outpost in the Himalayas and as a base of trade route to Tibet through Sikkim. General Lloyd was accordingly deputed to start negotiations with King of Sikkim for the transfer to Darjeeling in return for an equivalent in money or land. The negotiation ended in the execution by King of Sikkim of a Deed of Grant on 1st Feb 1835.  The land gifted to East India Co. in 1835 did not comprise entire Darjeeling of today instead it was a narrow enclave of 138 sq. miles and included sites of Darjeeling and Kurseong towns and touched the plains near Pankhabari.

In 1839, Dr Campbell was transferred to Darjeeling as Superintendent who devoted himself to the task of developing the station, attracting immigrants to the mountain slopes and stimulating trade and commerce. The population of the district developed from merely 100 in 1839 to 10,000 in 1849 mainly due to immigrants from neighbouring states of Nepal, Sikkim and Bhutan. Due to Campbell’s effort an excellent sanatorium was built, a Hill Corps established to maintain order and communication, 70 European style houses constructed,  bazar and roads built and experimental cultivation of tea, coffee and fruits started. When in 1849, Dewan Namgyal arrested Campbell and Hooker, British sent a fugitive expedition against Sikkim and British annexed 640 sq. miles of additional territory from Sikkim. Treaty of Tumlong signed in 1861 was great advantage to Darjeeling which secured full freedom for commerce and a road from Darjeeling to Teesta was constructed.

In the meantime, trouble arose with adjoining Bhutan and Bhutanese were constantly raiding the areas of Darjeeling. In 1863, Ashley Eden was deputed to negotiate with Bhutan and in 1864 a military force was despatched to Bhutan which resulted later Treaty of Sinchula in 1864 under that Bhutan Duars with the passes leading into the hills of Kalimpong were ceded to British. In 1866, the Darjeeling district can be said to have assumed its present shape and size of 1863 sq. miles and peace was established in all fronts hence began the march to progress and stability.