This volume is a translation of Ces Chretiens nos Freres and is the tenth volume in H. Daniel-Rop's great History of the Church of Christ. It covers the period 1870-1959 and gives a broad and comprehensive survey, from a Catholic viewpoint, of the activities of the Christian Churches throughout the world not in communion with Rome, including the Church of England, Eastern Orthodox, and the older Protestant faiths as well as some of the more recently founded denominations. This tenth volume pays particular attention to the Ecumenical movement and the work of the World Council of Churches.