The District was part of the dominions of the Raja of Sikkim. In 1706 what is now the Kalimpong subdivision of the District was taken from the Raja of Sikkim by the Bhutanese. The Rajas later became engaged in unsuccessful struggles with the Gurkhas who had sized power in Nepal and invaded Sikkim in 1780. During the next 30 years they overran Sikkim as far east as the Tista and conquered and annexed the Tarai. In the meantime war broke out between the East India Company and the Nepalese at the end of which in 1817 by the treaty of Titaliya the tract which the Nepalese had wrested from the Raja of Sikkim was ceded to the Company. The Company restored the whole of the country between the Mechi and the Tista to the Raja and guaranteed his sovereignty. Sikkim was thus maintained as a buffer State between Nepal and Bhutan.
The District was included in the Rajshahi Division until October 1905 when, as a result of the Partition of Bengal, it was transferred to the Bhagalpur Division. With the re-arrangement of the provinces it was retransferred to the Rajshahi Division in March 1912.
The District was formerly a non-regulation District, that is to say, Acts and Regulations did not come into force unless they were specially extended to the District. Darjeeling had no representative in the Legislative Council constituted under the Government if India Act 1919. It was excluded and declared a backward tract. The Administration of the District was not subject to vote of the Legislature. The effect of exclusion was that any Act passed by the Legislature which extended to the whole of Bengal automatically applied to the Darjeeling District, unless the Government in Council directed that the Act in question should not apply or that it should apply subject to such notifications as the Governor thought proper.