The Church of South India is the result of the union of churches of varying traditions Anglican, Methodist, Congregational, Presbyterian, and Reformed--in that area. It was inaugurated in September 1947, after protracted negotiation among the churches concerned. Organized into 16 dioceses, each under the spiritual supervision of a bishop, the church as a whole is governed by a synod, which elects a moderator (presiding bishop) every 2 years. Episcopacy is thus combined with synodical government, and the church explicitly recognizes that Episcopal, Presbyterian, and congregational elements are all necessary for the church's life. The Scriptures are the ultimate standard of faith and practice. The historic creeds are accepted as interpreting the biblical faith, and the sacraments of baptism and the Lord's Supper are recognized as of binding obligation.
Discussions concerning union had begun at a conference at Tranquebar (now Tarangambadi) in 1919, and in 1947, after India attained independence, the union was completed. The Church of South India has its own service book and communion service, both of which draw from several denominational sources. It is in limited communion with the Anglican Church and the Episcopal Church of the United States. The union, especially in its reconciliation of the Anglican doctrine of apostolic succession with the views of other denominations, is often cited as a landmark in the ecumenical movement .
The Church of South India has 3.8 million members and 14 000 congregations in 21 dioceses (including, for historical reasons, one diocese in northern Sri Lanka). The CSI runs 2000 schools, 130 colleges and 104 hospitals. In the 1960s the Church became conscious of its social responsibility and started organizing rural development projects. There are 50 such projects all over India, 50 training centers for young people, and 500 residential hostels for a total of 35,000 children.