The Meerut Diocese, originally part of the Agra Archdiocese, was established in 1956, with Bishop J.B. Evangelisti as its first Bishop. Father Pius, a priest from the Agra Archdiocese, transitioned to the Meerut Diocese and began his missionary work. He first served in Moradabad, where, alongside the Sisters of Saint Anna, he founded Saint Mary's Girls Higher Secondary School. His journey continued to Rampur, where he settled the Sisters of Saint Anna and acquired the old Nawab of Rampur's mansion, now home to a Parish Church and Technical School.

Father Pius then moved to Bilaspur, where he gathered Christian refugees from Punjab who had settled in the Terai region in 1947. With the assistance of Master Albert Ramsay, he organized the community, purchased 900 acres of land, and established fourteen villages, including Isanagar. He built schools, small hospitals, and roads, supported by the Sisters of Saint Anna, who continue their service today. Isanagar, designated as his headquarters, saw its first Mass under a Peepal tree in 1966, led by Father Pius, who became its first parish priest.

The parish extends to villages like Maryampur, Pius Colony, Bethania, Shanti Nagar, Chakki, and Anna Colony. A small unit, Manihar Kheda, 12 km away, was developed by Father Pius, with a hall built in 1992 by Father Bernard and later consecrated as a church dedicated to Saint John the Baptist by Father Albert. A school in Manihar Kheda, also dedicated to Saint John the Baptist, operates under the Sisters of CMC, with Father Vijay Anthony Rao currently serving as the parish priest.