This masterful work by Dr. Laurie Olsen uncovers the behind-the-scenes story of the Dogmatic Constitution on the Church Lumen Gentium VIII based on unpublished records from the Vatican Apostolic Archives, including internal memoranda, private notes, never-before-heard audio recordings of closed-door sessions, and more. This monumental achievement of archival research provides a window into what really happened at Vatican II—the council’s inner workings and maneuvers to steer Lumen Gentium VIII in a direction that would profoundly affect marian devotion and the study of mariology from that moment on.