Maundy Thursday, the Thursday of Holy Week, commemorates the Last Supper, at which, in Christian belief, Christ instituted the eucharist, and the washing of the disciples' feet. Its English name comes from the Latin mandatum, "commandment", from Christ's words at the foot-washing, "a new commandment I give you, that you love one another"; the evening liturgy re-enacts the washing of feet, in which a bishop, priest, or, increasingly, any leader washes the feet of members of the congregation in a gesture of servant love.
The day carries several distinct actions. In the West the evening Mass of the Lord's Supper opens the Triduum; afterwards the sacrament is carried to an altar of repose, the main altar is stripped bare, and a watch is kept, recalling Gethsemane. A separate morning Chrism Mass in each Catholic diocese blesses the holy oils for the coming year and the clergy renew their vows. In the East it is Holy Thursday, keeping the mystical supper. Across traditions the day binds together three things the church takes as inseparable: the eucharist, the priesthood, and the commandment of love expressed in humble service.