This paper traces the historical development of Karl Barth's ecclesiology by analysing three representative works: The Epistle to the Romans, the Göttingen Dogmatics, and the Church Dogmatics. It argues that Barth's theological turning point was a shift away from an early period Christology, which emphasised an eschatological time/eternity dialectic, culminating in the resurrection, towards a Christology that emphasised the anhypostatic union of Christ's two natures, that culminated in the incarnation. Thus Barth gave an increasingly positive valuation of the church as an historical institution.