Oscar Cullmann's 1962 revision of Peter in turn carefully treats the "Historical Question" and the "Exegetical and Theological Question" of the apostle Peter. While Cullmann cannot decisively confirm some of the details of Peter's life—his residence in Rome and the location of his grave, in particular—other details are described as more probable, such as Peter's travel to Rome and his martyrdom under Nero. Cullmann faithfully seeks Catholic-Protestant dialogue while maintaining that Jesus' words—"upon this rock I will build my church"—refer to the apostle alone and provide no historical basis for succession. The timeless quality of Cullmann's methods and his overwhelming concern for Christian unity are sure to inspire new generations of biblical scholars and contemporary theologians.