Darjeeling Diocese consists of three hill subdivisions of Darjeeling District (Darjeeling, Kurseong, Kalimpong), State of Sikkim and the country of Bhutan.
It was erected on 8th August, 1962 and was formed by separating Darjeeling District from the Church of Calcutta, and joining it to the Prefecture Apostolic of Kalimpong-Sikkim. In November 1997, the Church of the Siliguri subdivision of Darjeeling District was separated from the Diocese of Darjeeling to form the new Diocese of Bagdogra.
The Church first came to Darjeeling with the Irish Loreto Sisters in 1846, soon after the opening of the hill station of Darjeeling. The area was then under the ecclesiastical jurisdiction of Bishop Hartman of Patna Diocese and was staffed by Capuchin Fathers, who were mostly Italians. In 1886, when the hierarchy was established in India, the area comprising the present subdivisions of Darjeeling, Kurseong and Siliguri and the State of Sikkim was transferred to the jurisdiction of the Archbishop of Calcutta and came under the care of the Jesuits from Belgium.
In 1889, a Theologate for the Society of Jesus called St. Mary’s College was started at Kurseong. Up to the end of 1971, when the it was transferred to Delhi, the college contributed much to the expansion work in the district. Memorable among the missionaries of that time was Father M. Wery who worked in Kurseong, from 1932 to 1957, and is known today as the ‘Apostle of the Nepalese’ and Fr. A. Bossarts who started the first station in the Terai at Gayaganga in 1933 where he died in 1945, after years of service to the tribal labourers brought from Chotanagpur to work in the tea gardens of the plains.
In 1946, the English-speaking Jesuits of the Upper Canada Province came to the assistance of the Belgium Jesuits. They gradually took over the administration of the area, and in 1956 the Darjeeling Region of the Calcutta Province was created, and this became a Province of the Society of Jesus in 1997.
In the Kalimpong area, work started in 1881, when the Fathers of the Foreign Missions Society of Paris (MEP) came on a first visit to Pedong. Prominent among those French missionaries was Father Aguste Desgodins, a pioneer and scholar in Tibetan, who founded Pedong mission-post in November 1882, with hope of getting into Tibet via the Chumbi valley.