During the period of Khagada Nawab, Mohammed Fakiruddin, one Hindu saint arrived , he was tired and wanted to rest at this place, but when he heard that this place name is Alamganj ,the river name is Ramzan and the Jamindar name is Fakiruddin , he refused to enter at Alamganj. After that the Nawab decided and announced some portion from Kishanganj Gudri to Ramzan pool gandhi ghat as Krishna-Kunj . As time passed by the name gets converted to present KISHANGANJ.
Kishanganj was the old and important Sub-Division of Purnia district. After the long and hard struggle of Seventeen Years from people of Kishanganj including Social Workers, politicians, journalist, businessman’s, Farmers etc., the Kishanganj District came into existence on 14 January 1990.
During the Mughal period, the area was part of Nepal and was called Nepalgarh. When on the instructions of the Mughal emperor, Mohammed Reza captured the fort at Nepalgarh, the name was changed to Alamganj. It later became Kishanganj.
Kishanganj district occupies an area of 1,884 square kilometres (727 sq mi), comparatively equivalent to Maui in the United States.Kishanganj district is surrounded by Araria district in the west, Purnia district in the south-west, Uttar Dinajpur district of West Bengal on the east, and Darjeeling district of West Bengal and Nepal on the north. A narrow strip of West Bengal, about 20 km wide separates it from Bangladesh.
Kishanganj district is located between 250 20’ and 260 30’ north latitudes, and 870 7’ and 880 19’ east longitudes. Major rivers flowing through the district are Mahananda, Kankai, Mechi, Donk, Ratua and Ramzan Sudhani.
The district comprises only one sub-division, Kishanganj, which is further divided into seven blocks: Bhahadurganj, Dighalbank, Kishanganj, Kochadhaman, Pothia, Terhagachha, Thakurgunj.