From 1961 to 1965, the world closely watched the proceedings of Vatican II, the Catholic Church's council on the condition and future of the faith. Georgetown historian O'Malley presents the most thorough account of the proceedings of the council itself, from the time it was declared in 1959 until its conclusion in 1965, fulfilling the book's title. O'Malley gives a thorough and detailed history of the event, situating it in the longer history of the church and previous councils. But the bulk of the book concerns the characters and controversies of Vatican II itself, the biggest meeting in the history of the world. Though challenged by a conservative minority, the progressive majority of Vatican II reoriented and refashioned the Catholic Church: opening it to ecumenical relations, declaring its support for religious liberty and ending the practice of the Latin Mass. Infusing the council was the spirit of aggiornamento—Italian for updating. O'Malley shows how Vatican II allowed the church to modernize while also remaining true to its traditions and convictions.