Many of the brotherhoods go back to the sixteenth century, and a diocesan synod called by Cardinal Fernando Niño de Guevara in 1604 required them to make their station at the cathedral. The station is meant as prayer. The cathedral's dean says the brotherhoods do not simply cross one more stretch of the official route but enter the mother church of the archdiocese for a moment of prayer, recollection and encounter with the Lord. Under a project run jointly by the cathedral chapter and the council of brotherhoods, the brotherhoods prepare prayers and meditations for their members to pray as they pass through; those who process on Holy Thursday and through the night that follows, the night Seville calls the Madrugá, adore the Blessed Sacrament at the altar of repose.
The council of brotherhoods describes itself in its own history as an advisory body dependent on Church authority, and each year it publishes the list of brotherhoods that make the station at the cathedral. Routes and the arrangements inside the cathedral are set year by year.
Good to know before you go: for a Catholic visitor the order matters. Go first to the liturgies of the Triduum, the Mass of the Lord's Supper on Holy Thursday, the celebration of the Passion on Good Friday and the Easter Vigil, in the cathedral or a parish, and then join the street as an act of devotion. Wait for the council's list for the year before fixing which processions to see, since the days and routes are confirmed annually. The Church honors such processions and asks that they never replace the liturgy.