Tenebrae (/ˈtɛ.nə.breɪ/ or /ˈtɛ.nə.bri/—Latin for "darkness") is a Christian religious service celebrated during Holy Week within Western Christianity, on the evening before or early morning of Maundy Thursday, Good Friday, and Holy Saturday. Tenebrae is distinctive for its gradual extinguishing of candles while a series of readings and psalms are chanted or recited.
The Roman rite of Tenebrae was widely observed in the Catholic Church, until liturgical reforms in the second half of the 20th century diminished the practice. Tenebrae liturgy traditions also exist in Anglicanism, Protestantism, and Western Rite Orthodoxy.
In the Roman Catholic Church, "Tenebrae" is the name given to the celebration, with special ceremonies, of Matins and Lauds, the first two hours of the Divine Office, of the last three days of Holy Week. The traditions regarding this service go back at least to the ninth century. Originally celebrated after midnight, by the late Middle Ages their celebration was anticipated on the afternoon or evening of the preceding day in most places.