The use of bringing the olive or the blessed palm into our homes has a devotional origin and represent a wish for peace.
The great event is the Palm Sunday and Passion of the Lord Papal mass in Saint Peter's Square, at 9:30:
At 12:00 the Pope held the Angelus and the blessing ‘Urbi et Orbi ‘from the benediction loggia in Saint Peter façade.
The first celebration took place in Jerusalem at the end of the fourth century, while in the West the tradition was assimilated later. In Rome only from the end of the XI century. The reason was that this Sunday was dedicated to pre-baptismal ceremonies (baptism was administered at Easter) and to the solemn beginning of Holy Week