On this day four events are celebrated: the washing of the disciples' feet, the institution of the Mystery of the Holy Eucharist at the Last Supper, the agony in the garden of Gethsemane (but the liturgical texts do not dwell much on this), and the betrayal of Christ by Judas.  In certain cathedrals and monasteries, there is a special ceremony of feet-washing at the conclusion of the Liturgy, with the bishop or abbot taking the part of Christ and twelve priests representing the apostles.  At the Ecumenical Patriarchate in Constantinople, and at the centers of other Patriarchates and Autocephalous Churches, the Holy Chrism is blessed during the Liturgy on this day; but the rite does not take place every year.  The meaning of Holy Thursday is summed up in a text of singular beauty, repeated many times at the Liturgy, which combines the themes of eucharistic Communion, Judas' treachary, and the confession of the Good Thief: