In the first century, the early Christians celebrated every Sunday in commemoration of the resurrection of Jesus.
By the second century, they established a particular day for the celebration of the resurrection, which was connected to the Jewish Passover. Their observance began at sundown on Saturday evening. They called it the Night of the Great Vigil, a time of remembrance and expectation that lasted throughout the night so they could sing "alleluia" at dawn on Easter morning. It was during the Night of the Great Vigil that new Christians were received into the Church.
By the fourth century, it became customary for people to make pilgrimages to Jerusalem to celebrate what was called the “Great Week," which included Holy Thursday, Good Friday, the Easter Vigil and Easter Sunday. The diary of a woman named Egeria in 381 contains the first accounts of the special rites, prayers and devotions that took place in Jerusalem during the Great Week.
Over time, the practice of observing Holy Week spread throughout the Christian world, with prayers, historical re-enactments and special liturgies.
During the Middle Ages, the celebration of the Easter Vigil gradually fell out of practice. The important days of the week were Palm Sunday, Holy Thursday, Good Friday and Easter Sunday.
In 1955, the Vatican re-established the Easter Vigil as an important part of Holy Week observances.
During the Second Vatican Council (1962-65), the bishops called for the restoration of the early Christian rituals for receiving new Christians into the Church at the Easter Vigil.
In 1988, the Rite of Christian Initiation of Adults was issued.
Today, Easter Vigil with the Easter fire, the lighting of the paschal candle, the reading of salvation history, the celebration of the sacraments of initiation for catechumens and renewal of baptismal promises for the faithful is once again an integral part of Holy Week celebrations.
Source: Our Sunday Visitor