Although taking different forms and changing directions over the course of the centuries, the determination of the Church to create a place that was at the same time both the physical centre and the symbol of Christianity was concentrated in St Peter's. From the Middle Ages to the present day, a continuous flow of pilgrims has filled the Basilica; they have been present at the great events which have marked the history of the church. In this photographic text, St Peter's is presented just as it was conceived - as an immense space to receive the pilgrim in the heart of the church, in both the literal and symbolical sense of the word. Bruno Contardi's text introduces each image, critically reviews the fundamental stages in the reconstruction of St Peter's and discusses the theoretical and planning questions whch have influenced the definitive arrangements of the Basilica.