Holy Week (Latin: Hebdomas Sancta or Hebdomas Maior, "Greater Week"; Greek: Ἁγία καὶ Μεγάλη Ἑβδομάς, Hagia kai Megale Hebdomas) in Christianity is the last week of Lent and the week before Easter. It includes the religious holidays of Palm Sunday, Maundy Thursday (Holy Thursday), Good Friday, and Holy Saturday. It does not include Easter Sunday. In Eastern Orthodox tradition, Holy Week starts on Lazarus Saturday, the day before Palm Sunday. (Easter Sunday, for context, is the first day of the new season of the Great Fifty Days, or Eastertide, there being fifty days from Easter Sunday to Pentecost Sunday.)

Holy Week in the Christian year is the week immediately before Easter. The earliest Catholic allusion to the custom of marking this week as a whole with special observances is to be found in the Apostolical Constitutions (v. 18, 19), dating from the latter half of the 3rd century and 4th century. In this text, abstinence from flesh is commanded for all the days, while for the Friday and Sunday an absolute fast is commanded. Dionysius Alexandrinus in his canonical epistle (AD 260), refers to the 91 fasting days implying that the observance of them had already become an established usage in his time.^[1]

Palm Sunday is a Christian moveable feast that falls on the Sunday before Easter. The feast commemorates Jesus' triumphal entry into Jerusalem, an event mentioned in all four canonical Gospels. (Mark 11:1–11, Matthew 21:1–11, Luke 19:28–44, and John 12:12–19).

In many Christian churches, Palm Sunday is marked by the distribution of palm leaves (often tied into crosses) to the assembled worshipers. The difficulty of procuring palms for that day's ceremonies in unfavorable climates for palms led to the substitution of boughs of box, yew, willow, or other native trees. The Sunday was often designated by the names of these trees, as Yew Sunday, or by the general term Branch Sunday.

Lent (Latin: Quadragesima, "fortieth"^[1]) is an observance in the liturgical year of many Christian denominations, lasting for a period of approximately six weeks leading up to Easter. In most Western denominations Lent is taken to run from Ash Wednesday to Maundy Thursday (Holy Thursday) or to Easter Eve.

The traditional purpose of Lent is the preparation of the believer—through prayer, penance, repentance, almsgiving, and self-denial. Its institutional purpose is heightened in the annual commemoration of Holy Week, marking the death and resurrection of Jesus, which recalls the events of the Passion of Christ on Good Friday, which then culminates in the celebration on Easter Sunday of the resurrection of Jesus Christ.