• July 4, 1979: Established as Diocese of Rourkela from the Diocese of Sambalpur.
  • The Diocese of Rourkela was created by the Papal Bull “cum Cordi” dated July 4, 1979 by taking the entire civil district of Sundargarh from the diocese of Sambalpur in Orissa. At the time of erection of Rourkela, the diocese of Sambalpur, erected in 1951, comprised the four Orissa districts of Sundargarh, Sambalpur, Bolangir and Dhenkanal.

The new diocese of Rourkela is bounded on the north by Archdiocese of Ranchi and on the South by the diocese of Sambalpur to the west and the north-west lies the diocese of Raigarh, while the diocese of Jamshedpur and Balasore lie to the east and South-East.

Jesuit Missionaries began evangelization of this part of the Chotanagpur Mission, Fr Constant Livens (1856–1893) being the most prominent among them. After the Second World War, the Jesuits faced two major problems – personnel and finance. They, therefore, requested the Divine Word Missionaries (SVD) who had been working in the neighbouring states of Central India since 1932, to take up the Gangpur Mission in Northern Orissa. The SVDs set their feet in this mission land in 1948. The Late Bishop Herman Westermann, SVD, who had several years of experience in Central India, was ordained the first Bishop of Sambalpur in 1951. During his tenure as well as that of Bishop Raphael Cheenath, SVD (1974–1979), mission work in this ecclesiastical territory progressed in leaps and bounds.

Rt. Rev. Alphonse Billung, S.V.D. was appointed the first Bishop of Rourkela on November 3, 1979. Today the Diocese of Rourkela owes a lot to the relentless zeal and indefatigable labour of these eminent personalities, and their co – Missionaries – Priests, Brothers, Sisters, Lay people, generous benefactors and all well-wishers.