Sancte Dei, pretiose

You can read about this hymn from the Sarum Breviary, Sancte Dei, pretiose, at the Hymns and Carols of Christmas website, which also has a MIDI file of the melody.

The day of Saint Stephen falls on December 26.

Sancte Dei, pretiose

1. Sancte Dei, pretiose,
Protomartyr Stephane,
Qui virtute caritatis
Circumfulsus undique,
Dominum pro inimico
Exorasti populo

(Saint Stephen)