Diocese of Purnea covers a land area of 15,733.4 square kilometers. The diocesan territory consists of the flat alluvial bed of the Kosi river, the River of Sorrows.
The diocese of Purnea was created through a declaration of Pope John II on Aug. 11, 1998. Its history can be traced back to almost 240 years. Records of 1773 show that Purnea district was part of the vicariate of the Great Moghul, which was served by the Jesuits and later by the Carmelites. Subsequently, Rome attached Purnea to the neighbouring prefecture of Tibet under the Capuchins, with Patna as its headquarter. In 1820, it became part of the Agra vicariate. When Patna vicariate was created on Feb. 7, 1845, Purnea became part of it under the Capuchins.
The total population in the diocesan territory was 9,634,000 as of December 2016. Major Towns are Purnea, Katihar, Kishanganj, and Araria. The majority of the local people can be identified as Hindus. The vast majority of Christians of the region are Santhals, Oraons and Mundas.
Purnea is famous for spreading out Ramakrishna Mission, founded by Sri Ramakrishna's chief disciple Swami Vivekananda on May 1, 1897.
Languages spoken in the diocese are Hindi, Bangla, Santhali, Mundari and Oraon. Dialects in use are Surjapur, Polia, Angika and Maithli.
Purnea Bhagalpur diocesan territory falls within Bihar and Jharkhand states. Local civic bodies are governed under the Panchayat Raj system wherein elected representatives of the panchayats monitor development works of the village.
Road, rail and river are the routes of transport.
The per capita income was Rs. 4,435 ($90.75) as of September 2009.
Sugar production is a major industry. Paddy, maize, jute, wheat, moong, masoor, mustard, linseed, sugar cane and potato are the main crops cultivated.
All India Radio Purnea is active in the territory.
The literacy rate in the diocesan territory is 28.52 percent (female: 19.88 percent and male: 42.64 percent ).