This monograph defends the continuity of the liturgical reforms of Vatican 11 with the previous liturgical tradition by examining and comparing the prefaces for the Sundays of Lent in the Roman Missals of 1570 and 2002. That is examining whether or not the editio typica tertia of the Missale Romanum (MR 2002) shows any significant rupture from the Tradition as some writers claim. Dr Lionel maintains that the liturgical prayers show a continuous thread of connection not only between Vatican 11 and the reforms of the Council of Trent, but from the New Testament period to our own day. The study, which examines the question of continuity by comparing specific texts from the pre- and post-conciliar editions of the Roman Missal is the first of its kind in liturgical scholarship. The work offers a precise methodology for the future study on continuity by defining the three elements of continuity based on the teachings of the Catholic Church: substantial, biblical and traditional. Substantial continuity refers to the unity in the theological content of the prefaces from pre- and post-conciliar missals in spite of some variations. Biblical continuity indicates the correspondence between scripture readings of the day or the season and the words of the prefaces with their theological and liturgical significance. Traditional continuity points to the connection between the present texts and the mystagogical writings of the Fathers of the Church and prayers of ancient sacramentaries. Dr Lionel has for the first time attempted a serious scholarly investigation of the Trentine missal and that of 2002: an enormous work in terms of time,scholarly dedication and interpretative skills.