Karl Barth (1886-1968) was one of the great Protestant theologians of his time and greatly influenced the theological discussion in the 20th century. He was a follower of Dialectical Theology, one of the leading authors of the Theological Declaration of Barmen from 1934 and a promoter of many new basic insights into Reform Theology. His work led to reactions around the world, even in the Catholic Church and ecumenical circles. The author of the volume "Church Dogmatics" formulated many theological thoughts that have yet to be completely absorbed.Eberhard Busch was Barth's assistant from the fall of 1965 up to the latter's death on December 10, 1968. Today he is a Professor emer. for Systematic Theology from the University of Göttingen. When he worked for Barth he kept a diary in which he entered what he was experiencing and hearing. All the themes that concerned Barth at that time may also be found in the diary: Whereas the Protestant thoughts on the renewal processes of Catholicism in the light of the Vatican Council were originally of major import, thereafter his work on the teachings concerning baptism, his seminars at the university, visits and correspondence from friends, and his own battle with aging and death came to become essential to him.Barth himself never wrote an autobiography but was aware of the notes his assistant was making and was agreed to these efforts. Eberhard Busch has since composed these texts, continually orienting himself to the short notes he took on his daily work with Barth. These are supplemented by the many ideas Barth passed on to him, trusting that they would thus be preserved.