Australian evangelicals entered the 1960s confident that the ‘modest religious boom’ of the postwar period, capped by the extraordinary success of the 1959 Billy Graham crusade, would continue. Their confidence was justified: indicators everywhere of growing religious activity were undergirded by an assumption among civic leaders and the general public that Australia, part of ‘Greater Christian Britain’ or ‘Christendom’, was avowedly a ‘Christian nation’. By the return of Billy Graham for his final Australian crusade in 1979, those indicators had dived and that consensus had died. This prologue sketches out both the intensity and the scale of the changes evangelicals faced as they encountered the end of Christendom during the long 1960s.