Palm Sunday is the last Sunday of Lent. It is always the start of Holy Week and the last Sunday of Lent. It is one of the events that is mentioned in all four Canonical Gospels. It would seem according to the Gospel of John that just a week prior, Jesus was in Bethany having dinner with Lazarus, Mary and Martha and systematically the Church has the the Cycle A gospel for the 5^th Sunday of Lent  is Lazarus Sunday.

While in Bethany,  Gospels describe how Jesus had sent two disciples  on ahead to find a colt. Some say that Jesus had this already prearranged with Simon the Leper while others say Jesus found this particular colt to ride back through the gates of Jerusalem. The Gospel all go on to say how some lad down palm branches in order to make the ride more comfortable. There was also the description of people singing Psalm 118.

 Although depicted in art though the ages of Jesus passing though the Golden Gate of Jerusalem, there is nothing concrete in the Synoptic Gospels that would support this. However, the reciprocal though and why the belief is held that Jesus did pass though the Golden Gate is because as the Messiah this would be the only way He could enter Jerusalem. There are some scholars who want to say that he entered though the southern part of the city that had the stairs that lead directly to Temple Mount because that makes more sense.

Though history , there have always been  reenactment of the events of Jesus triumphant returned. The custom of the use of pals has a long history and harkens back the Old Testament. According to the Hebrew Bible Joshua also made a similar ride and was treated to the same way. 

Even more interestingly is that many of the Pre-Christian religion also have similar stories of their central figure returning to the holiest city and be greeted in this manner.  A prime example of this was Dionysus/Bacchus , the Greek god of Wine.  There are several parallels that can be drawn between Dionysus and Jesus, including Rustic Dionysia, or Christmas on December 25^th. And in Euripides Bacchae, there is a similar story of how Dionysus was arrested and questioned by Pentheus, very similar to how Jesus was arrested and brought before Pilot. In this story Dionysus returns much the same way Jesus returned to the Holy City in a triumphant manner on Palm Sunday.

The palm branch itself that was used was also symbolic. It was deeply rooted in Jewish tradition and is mentioned in the old testament book of Leviticus (23:40). The passage says  .And ye shall take you on the first day the fruit of goodly trees, branches of palm-trees, and boughs of thick trees, and willows of the brook; and ye shall rejoice before Jehovah your God seven days..  This addresses the use of palms as well as the seven days between Palm Sunday and the Resurrection/Easter Sunday. Its though this act of waving palms and making a path for Jesus with the Palms that Palm Sunday has gotten its name.