When Gregory the Great became pope at a time of political and religious crisis, he assumed responsibility for what had formerly been imperial duties. As Susanne Barth shows in this thorough historical analysis of his complete works, both his writings and deeds pay testimony to this fact. With the grace of charity evolving into a central aspect of Gregory's theology, he describes church as a community of reciprocal care. In the end, the benefit of the proximate - the utilitas proximi - becomes the ultimate touchstone for ethical action, which likewise determined Gregory's own work.