"At the beginning of the meeting Cardinal Ottaviani said that, to speed the work up, the experts will speak only if they are asked a question. At my side, Rahner was champing at the bit, and said to me what are we doing here . . . ?'" (Wednesday 3 June 1964) Yves Congar, OP, was one of the most important and influential theologians of the twentieth century. Much of this influence came as a result of his role as theological advisor to the bishops who participated at the Second Vatican Council (1962-1965). After working under a cloud of ecclesiastical censure and suspicion in the decade prior to its start, Congar was, from beginning to end, an influential day-to-day participant in the council's work. He also managed to keep detailed personal notes throughout the time. At long last, the council diaries of Yves Congar are available in English! This material is a treasure trove of information and insight for anyone interested in the history of that council and its remarkable and historic teaching. It provides a window into the council's workings and the development of what would become a series of historic documents and declarations. It also offers Congar's own down-to-earth and personal perspective on many of the other remarkable figures who played a role in the council.