Holy Week is the last week of Lent.
The character of Lent changes with Palm Sunday of the Passion of the Lord. The liturgy on this day begins with Christ’s messianic entry into Jerusalem when the crowds acclaim him as king with palm branches and exultant Hosannas. Each time we sing the Holy Holy at Mass, we remember this joyous acclamation. In this rite, the Church acknowledges the risen Lord present among us. Where possible, a significant procession (from one church to another) should be arranged or at least a procession into the church with all the people carrying branches.
Then, with the Collect of the Mass, the mood changes. We look back to the passion and death of Christ which led to his glory. The gospel is a solemn reading of the Passion of the Lord from Matthew, Mark or Luke; it serves as a kind of overture to Good Friday which centres on the Passion of Lord from John’s gospel. Red vestments make the connection visually. So with Palm Sunday of the Passion of the Lord, the scene is set for the great Easter Triduum.
The prayers and reading of the following days focus quite directly on the forthcoming Paschal Mystery. Holy Week ends on Holy Thursday before the evening Mass of the Lord’s Supper which marks the beginning of the Easter Triduum. The liturgical colour for these days is violet like the rest of Lent. Like the days in the octave of Easter, the weekdays of Holy Week have a high rank in the liturgical calendar, more important even than Solemnities. So, for example, if the Solemnity of the Annunciation of the Lord (25 March) should fall in Holy Week, it is postponed until the second week of Easter.
The Roman Missal includes the Chrism Mass for the blessing of the holy oils on Holy Thursday though, in Australia, it is usually anticipated by a week or more so that there is time to distribute the newly blessed oils to all the parishes. This Mass is only celebrated in the cathedral by the bishop. Its place in Holy Week makes a link with the sacraments of Christian Initiation to be celebrated at the Easter Vigil. Then, throughout the year, the oil of catechumens is used in the baptism rite and the consecrated holy Chrism is used in both baptism and confirmation (as well as ordination). The oil of the sick is used for healing in the sacrament of anointing. The holy oils speak of our belonging to Christ and our participation in the Paschal Mystery.