The subseries consists of records that document the relationship between the Catholic Archdiocese of Edmonton and the Holy See and includes information files on the Vatican, Holy See and Rome as well as information files on each of the popes, records related to the church councils (such as Vatican II), the Synod of Bishops and Canadian Cardinals.

The subseries consists of records that document the relationship between the Archdiocese of Edmonton and other episcopal entities such as other dioceses/archdiocese in Canada, the United States and overseas, the Canadian Military Ordinate, as well as Ukrainian Eparchies and various divisions of the Orthodox Church.

The subseries also consists of records that document the relationship between the Archdiocese and other episcopal entities in Alberta such as the Assembly of Western Catholic Bishops and the Alberta Conference of Catholic Bishops (ACCB), the Western Ecumenical Conference, the Alberta Church Consultation Committee, and the Alberta Diocesan Chancellors.

Finally the subseries consists of records that document the relationship between the Archdiocese and other non-Catholic Christian entities and includes correspondence with Anglican and Lutheran Bishops as well as other church leaders in Alberta.

Sub-subseries consists of bound letter books of out-going correspondence of Rev. Leduc in his capacity as Chancellor, 1884-1918; Rev. Emile Legal in his capacity as Co-Adjutor Bishop and Bishop of the Diocese of St. Albert and as Archbishop of the Archdiocese of Edmonton, 1897-1920; Rev. Vital Grandin in his capacity as Bishop of the Diocese of St. Albert, 1877-1902; indexes of letter books of Bishop Grandin and Bishop Legal, 1896-1920.

These letters are primarily of an administrative nature.