HE IS RISEN — The resurrection of Christ is depicted in this fresco by Giotto di Bondone from the Scrovegni Chapel in Padua, Italy. Easter Sunday is March 23.

During this, the holiest week of the year, Lent ends and the Easter triduum - a single three-day celebration of the Paschal mystery - begins with the Mass of the Lord's Supper on Holy Thursday evening.

Holy Thursday is the commemoration of the Last Supper when Jesus instituted the Eucharist and established the priesthood. During Mass the chrism and holy oils, used for baptism, confirmation and the anointing of the sick are brought forward. Additionally, this Mass includes the simple rite of washing of the feet. The Eucharist is celebrated and following the prayer after Communion, the Blessed Sacrament is transferred to a place of reposition.

Good Friday, the most somber day of the church year, is a day of fasting and abstinence. Additionally, it is the only day of the year in which Mass is not celebrated. The solemn liturgy this day is called the Celebration of the Lord's Passion. The readings on Good Friday are from the book of the Prophet Isaiah and from the Letter to the Hebrews. At the Gospel, we hear John's proclamation of Our Lord's Passion. The second part of the liturgy is the veneration of the cross, which is followed by a Communion service.

LAST SUPPER — An apostle (left) leans over the bread held by Christ in this painting of the Last Supper by Mariotto di Nardo. The Easter triduum begins with the evening Mass of the Lord’s Supper on Holy Thursday, March 20.

Holy Saturday is a day of waiting, commemorating the day Christ was in the tomb. The Easter Vigil takes place at night. After evening has fallen, the vigil begins with a "service of light." Some of the faithful gather around a fire to light the Easter candle. The priest, who is dressed in white vestments, lights the symbolic candle and the incense. Then, he and other participants process toward the church.

Saturday's Liturgy of the Word contains between three and seven readings from the Old Testament. The story of the Hebrews deliverance from slavery in Egypt is always included. Each reading is followed by a psalm. Following the readings, the altar candles are lighted, illuminating a church that is decorated in honor of the risen Lord. The opening prayer for the vigil is recited, followed by New Testament readings from the Romans and from Matthew.

The Easter Vigil is the time when the most new Catholics are received into our faith communities. Those who are being baptized are presented and assembled around the baptismal font, where they profess their faith and receive the sacrament. Following the baptism, the faithful renew their own baptismal vows. The priest sprinkles the assembly with holy water and the elect are received into the church and confirmed. Then, the Liturgy of the Eucharist begins.

THE CRUCIFIXION — An illustration (right) from a 13th-century Book of Hours depicts the crucifixion of Christ. Good Friday is marked March 21 this year. The artwork is part of the Rosenwald Collection at the National Gallery of Art in Washington.

With the Easter Day Mass, the faithful celebrate the resurrection and the triumph of the Lord. The readings this day are from the Acts of the Apostles, the Colossians and the Gospel from John, all focusing on Jesus, his ministry and his resurrection. After the homily, the faithful renew their baptismal promises.

On Easter Sunday, the triduum is concluded liturgically with Evening Prayer in the late afternoon or early evening. That's when the Easter Season, the 50 days from Easter Sunday until Pentecost, begins.