Church of South India
 
The C.S.I. was inaugurated on 27 September 1947 at St. George's Cathedral, Madras (Chennai). It was formed by the union of Anglican, Methodist, Congregational, Presbyterian, and Reformed churches in South India. The inspiration for this Union was drawn from the words of Jesus Christ as found in John, 17:21 - That they all may be one; as thou, Father, art in me, and I in thee, that they also may be one in us: that the world may believe that thou hast sent me. "That they all may be one" is the motto of the Church of South India and is incorporated on its logo.

The inauguration of the Church of South India was a historic event in Christendom where, for the first time, churches with Episcopal and non-Episcopal traditions decided to form a union. The C.S.I. was one of the earliest forms of the united and uniting church.
 
The Church is organized into 22 Dioceses, each under the supervision of a Bishop, including one Diocese in Jaffna, Sri Lanka. The Church is governed by a Synod with its headquarters in Chennai, which meets every two years to elect a presiding Bishop, called Moderator, who serves as head of the church.