The Union of Myanmar geographically, ethically and politically falls into 7 Division and 7 states. The Diocese of Pathein is situated squarely in the Ayeyarwaddy Division which is spread over an extensive area of some 18,089 square kilometers and has as of 2009 a population of 5,575,410. It borders in the north on Bago Division which includes the diocese of Pyay. On the eastern side there is a Yangon Division, containing sprawling archdiocese of Yangon. To the southeast it has the Mon State and the Tinintharyi Division with the diocese of Mawlamyine. Pathein diocese is situated in the extreme southern part of Myanmar, its extensive course bounded by the Bay of Martabin. The bulk of the entire Diocese of Pathein is located in the delta region of Myanmar. The Ayeyarwaddy, the longest river in the country, origines in the north and ultimately finds the way down south, criss-crossing this whole area with its rivulets - bigger and smaller before flowing into the Bay of Bengal. It is particularly due to this fact that the delta is known ''Granary of Myanmar". The whole country has to rely on the delta for food (rice) the greatest production of the country. This delta area reports by far the highest output of paddy in the country. The diocese is covered by paddy fields and wet lands criss-crossed by numerous rivers and rivulets, flowing to the Bay of Bengal in the south. Most of the region is mainly inhabited by tribal Kayin (Karens) and has a population of about 5.6 millions.
The Diocese of Pathein (Bassein) was officially erected in 1954 when Pope Pius XII established the catholic Hierarchy in Burma. Apostolate first started among the Karens of the Delta area in 1884 by an Italian priest, Father Dominic Tarolli who came to Burma with Bishop Cao in 1831.
Later in 1846, he was joined by Father Pogolotti - an Oblate cleric earlier ordained at Amarapura in 1843. Myaungmya was fixed as their headquarters or mission Center. Father Tarolli, however, was made prisoner during the second Anglo-Burmese War in 1852. The mission establishment were totally destroyed.
When Bishop Bigandet arrived from France in Burma in 1856, he appointed Fathers Lacrampe and Naude to evangelize this area. At the cost of much sacrifice and toil, early intrepid pioneers Fathers Lacrampe, Naude and Tardivel managed to establish a flourishing mission. Kanazoggon became the Mission Centre for Father Lacrampe. He soon set up a church, a clergy house and a school and by 1862 there were already one thousand Catholics.
Father Naude, instead, went across to Maryland and opened up a Mission there. Other outstanding missionary figures like Father Tardivel, Father Bringaud, Father Rouver, Father Maigre and Father Boudard did much to spread the Good News throughout this difficult virgin area; a name that stands out at this time was that of Father George D'Cruz who initiated the Apostolate of the Press among the Karens.
The tireless and zealous effort of those pioneers compelled with the sweet and toil of Burmas's own sons - the native priests, the Church in Pathein steadily developed, 1954 was a memorable year and one of tremendous joy - the first ever Bishop of Pathein - Monsignor George U Kyaw had his episcopal ordination.
Bishop George U Kyaw administered the Diocese from 1955 to 1967. Father Joseph Mahn Erie succeeded him as the next bishop. He was solemnly ordained at St. Mary's Cathedral in Yangon by the apostolic Delegate, Monsignore G.Capri, on June 12, 1968. Bishop Mahn Erie served the Diocese till his resignation in the middle of 1982. The elderly priest, Father Joseph Velerius Sequeira, took over as Bishop of Pathein later in 1985.
On April 27, 1988 Father John Gabriel was appointed auxiliary bishop of Pathein. At that time Bishop Sequeira served the Diocese until 1992. He retired due to his advanced age when Bishop John Gabriel was installed as bishop of Pathein on Feb. 23, 1992.
Unfortunately, Bishop John Gabriel's time at the episcopal office lasted only for two and a half years. He hardly lived long enough to see the fruits of his toils and labors. He died on Aug. 14, 1994. On his demise, Monsignor Paulinus Mahn Ei Shaung was elected Vicar Capitular of the Diocese of Pathein. Finally, after a couple of years, Bishop Charles Bo, SDB (the incumbent Bishop of Lashio) was appointed to the see of Pathein as its fifth Bishop - on May 24, 1996. He was officially installed on Aug. 25, 1996.
Far-sighted, being energetic and willing to serve and develop the Diocese of Pathein, Bishop Charles Bo, SDB , took a faithful and daring step to animate and convene a Diocesan Synod Dec. 12 -20, 1997 that has been giving birth to all developments of the diocese.
On March 22, 2003, Father John Hsane Hgyi was appointed Auxiliary Bishop of Pathein and finally was installed as Bishop of Pathein on Aug. 24, 2003, when Bishop Charles Bo, SDB, became Archbishop of Yangon.