In a land area of 38,700 square kilometers, the diocesan territory covers civil districts of Darrang, Udalguri, Sonitpur, Lakhimpur and Dhemaji on the north bank of the Brahmaputra River; and Rupahihat, Kaliabor and Samuguri subdivisions of Nagoan district on the southern bank of Brahmaputra.
Tezpur is the biggest town in the diocese.
In Tezpur diocese, the population is 8,705,620 at end of 2017. The major ethnic communities are Assamese, Mundas, Kharias, Oraons, Santals, Orias, Lohars, Boros, Garos, Rabhas, Deoris, Rajbongshis, Misings, Tiwas, Karbis, Nishis, and Apatanis.
English, Assamese, Hindi, Sadri, Mundari, Oraon, Kharia, Santali, Boro, Garo, Rabha and other local dialects are the languages used in the diocesan area.
On May 10, 1964, Pope Paul VI raised Tezpur to an Episcopal See, and nominated Orestes Marengo, SDB, as the administrator of the newly erected diocese of Tezpur. He took charge of the diocese on Aug. 23, 1964. By his pastoral care, Bishop Marengo was able to consolidate the new Christian communities and bring about development in the diocese. He resigned in 1969. Father Joseph Mittathany was nominated the second bishop of the diocese on June 26, 1969, and he was ordained bishop and installed on Sept. 27, 1969.
Bhutan, the independent kingdom in the Himalayas, formed part of the diocese till 1976. It was separated and attached to the diocese of Darjeeling on Jan 20, 1975.
John Paul II erected the diocese of Imphal, Manipur, on April, 2, 1980 and transferred Bishop Joseph Mittathany from Tezpur to Imphal as its first ordinary. Father Mathew Kottaram was elected the vicar capitular. Bishop Robert Kerketta, SDB, who had been bishop of Dibrugarh from 1970, was transferred to Tezpur, and took charge of the diocese on Jan. 31, 1981.
On Dec. 7, 2005, the Holy See announced another bifurcation of Tezpur and creation of the diocese of Itanagar, Arunachal Pradesh, with Bishop John Thomas Kattrukudiyil (of Diphu diocese) as it first ordinary. The erection of the diocese and installation of Bishop John Thomas took place on March 12, 2006. The diocese of Bishop Robert Kerketta after shepherding the diocese of Tezpur for a long period of 27 years retired on Dec. 3, 2007, and was succeeded by Bishop Michael Akasius Toppo.
The big towns are managed by corporations. The villages and small towns are administered by elected local bodies called panchayats and municipalities, respectively.
The diocesan area is well connected in terms of transport infrastructure by roads. The nearest airport is in Guwahati city which is 185 kilometers from Tezpur.
The per capita income in the diocesan territory is Rs 14,950 ($328) as of January 2010. Agriculture and horticulture are the main sources of income. The territory also has tea estates, textile industry, and jute mills.
Government and private operators provide extensive telecommunication facilities in the diocesan area. The diocese is well connected by local cable TV networks.
Approximately 70 per cent is the literacy rate in the diocesan territory.
