Holy Thursday is the commemoration of the Last Supper of Jesus Christ, when he established the sacrament of Holy Communion prior to his arrest and crucifixion. It also commemorates His institution of the priesthood. The holy day falls on the Thursday before Easter and is part of Holy Week. Jesus celebrated the dinner as a Passover feast. Christ would fulfill His role as the Christian victim of the Passover for all to be saved by His final sacrifice.
The Last Supper was the final meal Jesus shared with his Disciples in Jerusalem. During the meal, Jesus predicts his betrayal.
The central observance of Holy Thursday is the ritual reenactment of the Last Supper at Mass. This event is celebrated at every Mass, as party of the Liturgy of the Eucharist, but it is specially commemorated on Holy Thursday.
He also establishes the special priesthood for his disciples, which is distinct from the "priesthood of all believers." Christ washed the feet of his Disciples, who would become the first priests.
This establishment of the priesthood reenacted at Mass with the priest washing the feet of several parishioners.
During the Passover meal, Jesus breaks bread and gives it to his Disciples, uttering the words, "This is my body, which is given for you." Subsequently, he passes a cup filled with wine. He then says, "This is my blood..." It is believed those who eat of Christ's flesh and blood shall have eternal life.
During the Mass, Catholics rightly believe, as an article of faith, that the unleavened bread and wine are transformed into the body and blood of Jesus Christ through a process known as transubstantiation. There have been notable Eucharistic miracles attributed to this event, such as bleeding hosts (communion wafers).
The Last Supper is celebrated daily in the Catholic Church as part of every Mass for it is through Christ's sacrifice that we have been saved.
On the night of Holy Thursday, Eucharistic Adoration of the Blessed Sacrament takes place where the faithful remain in the presence of the Eucharist just as the Disciples kept a vigil with Christ.
Following the Last Supper, the disciples went with Jesus to the Mount of Olives, where he would be betrayed by Judas.
The Last Supper has been the subject of art for centuries, including the great masterpiece by Leonardo Da Vinci.
The cup used by Jesus is known as the Holy Grail. Although it has been rumored to exist throughout history, it is almost certainly lost to time. There is no reason to believe the cup would have been outstanding in any way, and was likely a typical drinking vessel, indistinguishable from many others. Still, many myths continue to revolve around the artifact, and it remains a target for treasure seekers and a subject of entertainment. There is an incalculable abundance of art and tradition surrounding the Last Supper which has been celebrated by Christians since the last days of Christ until now.
At every hour of every day, somewhere around the world, Mass is being said and Communion taken. This has been happening incessantly for at least several hundred years. For nearly the past two thousand years, not a single day has gone by without a Mass being celebrated in some fashion. Therefore, anyone who celebrates the Mass participates in a daily tradition that is essentially two thousand years old.