It was founded in 1934 as the
Church in Siam with the intent of forming a single ecumenical denomination to include all Protestant churches in Thailand. Other than a small number of
American Baptist and British
Churches of Christ congregations, most of the original member churches were originally
Presbyterian congregations, many of which were started by missionaries from the
American Presbyterian Mission Board. The merger also included
Lutherans from the German Marburger Mission. The C.C.T. originally had seven districts, six geographical and one ethnic
Chinese. Except for a brief period during
World War II,
Presbyterian missionary influence remained predominant in the C.C.T. until the late 1970s. ==Mission==