 His grandfather was Hans von Dohnanyi, German jurist and German resistance fighter and his great-uncle was Dietrich Bonhoeffer, Lutheran pastor and a co-founder of the Confessing Church, both of whom were executed by the Third Reich.Dohnányi studied acting at the Hochschule für Musik und Theater Hamburg.He appeared on the legitimate stage in Hamburg, Zurich, and Frankfurt before working in television, where he appeared in several television movies.