In a land area of 8,167 square kilometers, the diocesan territory covers East and West Garo Hills districts and the part of Goalpara district south of Brahmaputra River in Megahalaya.
Tura is the biggest town in the diocese. William Nagar and Resubelpara are the other important towns in the diocese.
In 2017, the total population in the diocesan area is 1,144,167. Garos, Rabhas, Koch, Hajong are the major ethnic groups.
Garo, Rabha, Assamese, Khasi, Bengali, English are the languages used in the diocesan territory.
Although Christianity took its roots in Garo Hills as early as in 1867, it was only in 1933 that Catholic missionaries began organized evangelization work among Garos. Prior to 1933, some missionaries had occasionally visited areas inhabited by Garos. Father Rudolf Fontaine, a Salvatorian priest then residing in Guwahati, was the first Catholic Priest to visit Garoland in 1913. It is recorded that during the time of the Jesuit missionaries (1914-1922), Father Carberry SJ visited Laskarpara, a village of the Garos, in 1921.
The first Garo Catholics in Garo Hills were those baptized by the Holy Cross Fathers in the present Bangladesh and then migrated to Garo Hills, especially to those villages near Baghmara. The first apostle of Garo Hills was Peter Shem Momin, a Garo who received the Catholic Faith while undergoing agricultural training in Shillong. He was responsible for the early conversions at Laskarpara, Chotcholja, Damit Apal, Kharkutta and Dilma.
The first Salesian Missionary to tour Garo Hills was Father Gil in 1923. Fathers Piasecki and Marmol who visited Garo Hills and also those villages on the Baghmara site via Mymensing once a year followed him. In 1931, Msgr. L. Mathias, the then Prefect Apostolic of Assam, appointed Fathers Pianazzi and Rocca to work among the Garos. As they were not allowed by the Government to reside in Garo Hills, they took up residence at Dhubri in 1932. In 1933, the Fathers managed to obtain from the then DC, Mr. William Shaw, permission to stay in Garo Hills and thus opened the first Catholic mission at Tura. From then on many European priests of the Salesians of Don Bosco have worked tirelessly to spread the Gospel in Garo Hills.
The missionary endeavors in Garo Hills received a great boost with the arrival of missionaries from South India. The first Indian missionaries to set foot in Garo Hills were Fathers M.P. Alexander and Mathew Elanjipuram who came to Garo Hills in 1956. Father E.O. Mathew in 1959 and Fathers George Mamalassery and George Elavankunnel in 1960 followed them. In the year 1970, the MSMHC Sisters, the Missionary Congregation of Blessed Sacrament Fathers and some diocesan priests from Changanacherry diocese volunteered to work in Garo Hills.
Bishop O. Marengo SDB, former ordinary of Dibrugarh and Tezpur, was appointed Episcopal Vicar in 1972. On April 7, 1973, Tura was made a diocese by detaching territories from the Archdiocese of Shillong-Guwahati with Bishop Marengo as Apostolic Administrator. The diocese had at that time around 40,000 Garo Catholics spread over the entire Garo Hills and the Goalpara and Kamrup districts of Assam. There were 6 parishes and a total of 21 priests: 16 religious and 5 diocesan. The sisters were only 26 in number.
The making of the new diocese accelerated the growth of Church in Garo Hills at all levels. New parishes were opened at Selsella (1973), Tikrikilla (1974), Chokpot (1974), Dadenggiri (1976), Mendal (1977), Williamnagar (1977), Garobadha and Wadanang (1978). The Medical Mission Sisters (1971), the MSFS Fathers and the Daughters of St. Thomas (1975) now joined the missionaries already working in Garo Hills. Numerous young men from the South of India who later became priests were recruited now for the new diocese. In 1976, the first Garo priest Father Crispinus Rangsa from Baghmara was ordained a priest.
Pope John Paul II relieved Bishop Marengo of the office of Apostolic administrator on Feb. 8, 1979 and appointed Father George Mamalassery of the diocesan clergy as the first bishop of Tura. The new bishop was consecrated on March 18, 1979. The first task of the new bishop was to build proper infrastructure in all the existing parishes. Putting all his abilities into work, he completed in each of these parishes a church, a presbytery, hostels for both boys and girls, a convent, a school and a dispensary. In order to promote local vocations to the priesthood, a three-storey seminary building was built in 1983.
Many new religious congregations were invited to work in the diocese. They were: Sisters of Mary Immaculate (1980), Salesian Sisters (1982), Franciscan Brothers (1983), Claretian Fathers (1984), Missionaries of Charity (1985), RNDM (1985), Sisters of the Cross of Chavanod (1986), SMMI (1987), Holy Cross Sisters, Menzingen (1993), Montfort Brothers (1995), Daughters of St. Francis De Sales (1996), Sacred Heart Sisters (1998), Capuchin Fathers (1999), Jesuits (2003), Disciples of Divine Master (2005) and Ursuline Sisters (2006).
Bishop George opened many more new parishes and built many spacious churches at key centers. The new parishes opened were: Mangsang and Nangwalbibra (1979), Purakasia (1981), Chimaimpel (1984), Rongkon (1986), Rongara, Ampati and Cathedral (1989), Songsak (1992), Araimile (1994), Mendipathar (1995), Rabhagre, Rajabala and Jengjal (1996), Siju (1997), Samanda (2000), Mrongre and Dumnikura (2003), Kharkutta, Chidimit and Chapahati (2004) and Dawakgre and Danakgre (2005). In each of these parishes a church, a presbytery, hostels for both boys and girls, a convent, a school and a dispensary were built.
In 1987 Bishop George invited the Salesians of Don Bosco to open the much needed Catholic College at Tura to the great benefit of many Catholic boys and girls. In 1989 a parish for Rabhas and Boros by the name of Mukti Dada Ashram was opened in Tikrikilla under the care of Father George. In 1991, a pastoral centre was opened adjacent to the bishop's house. The establishment of the 150 bed Holy Cross hospital at New Tura in 1993 was a major event in the history of the diocese. 0n March 29, 1994, an interdenominational Garo Bible was released.
In 1995 when the new diocese of Guwahati was established, Damra parish, having a large number of Garo and Rabha Catholics, was given over to the new diocese. The opening of the Home for the disabled and normal School at Danakgre in 1996 was a significant event in the history of the diocese. In the same year a Marriage Tribunal with qualified personnel was established in the diocese. On July 30, 1998, barely a month before his 94th birthday, Bishop Emeritus Marengo was called by God for his eternal reward. The Silver Jubilee of the Episcopal Ordination of Bishop George Mamalassery was celebrated on March 14, 2004 at Tura. To mark the occasion, the Simonetti Nursing School at Danakgre was blessed in the presence of all the bishops of the region.
In the same year, on June 17, 2004, Pope John Paul II, nominated Father Andrew R Marak as the coadjutor bishop of Tura. He was ordained a bishop by Archbishop Pedro Lopéz Quitanta, Apostolic Nuncio to India on Oct. 3, 2004 at Tura.
In the following year, on May 31, 2005, Father Mathew Elanjipuram, the first Indian and diocesan priest to work in Garo Hills, passed away.
The year 2006 saw further progress of the diocese. The SMI convent and the girls' hostel at Rajabala were opened that year. Spacious churches were also built and consecrated at Dumnikura, Chapahati, Karkhutta and Damas. Existing schools at Araimile, Purakasia, Chokpot, and Rongsak were extended. Work of a Convent and hostel at Karkhutta, a Higher Secondary School at Dengagre (Williamnagar) and a church at Walbakgre, near Holy Cross Hospital was begun at a war footing. The Social Services of the diocese were reorganized and brought under the banner of Bakdil with a full-time director. In the same year, the Simonetti Nursing School adjacent to the Holy Cross Hospital, became fully functional with classes for General Nursing Students. On completion of 75 years of age on April 22, 2007, Pope Benedict XVI accepted the resignation of Bishop George, and appointed Bishop Andrew R. Marak as the Bishop of Tura. Bishop George has rendered yeoman service for well over 28 years to the people of Garo Hills both as a religious leader and a Social worker.
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.
India Rupees 18,274 (USD394 as of January 2010) is the per capita income in the diocesan territory. Farming is the major occupation, especially shifting cultivation is practiced in the area.
Government and private operators provide extensive telecommunication facilities in the diocesan area. The diocese is well connected by local cable TV networks.
55 per cent is the literacy rate in the diocesan territory.