The cultural, social and political dominance of Christendom in `the West' over 2 millennia makes the Christian Church a shaper of the modern world beyond the strictly religious. Its interactions with other world religions have caused tensions at times and not least in the modern world because of a profound ignorance of the history of ideas which has brought the Church to where it is today. The Christian Church today has many faces, behind which lies a history of thought, effort and struggle. The I.B.Tauris History of the Christian Church proposes to provide the 21st century reader with a command of the sequence and network of ideas of what the Church is and of the history of this long tradition.