I. Pater Creator Omnium
On all principal Feasts.
God, Creator of all things, our God, in your pity, have mercy on us.
To you, Christ, King of kings, rejoicing in praise together, we pray, have mercy on us.
To you belongs praise, virtue, peace, and dominion forever and ever, have mercy on us.
Christ, our only king, co-eternal Son of the gracious Father, have mercy on us.
You saved lost humanity, restoring all from death to life, have mercy on us.
Jesus, good Shepherd, so the sheep of your pasture will not perish, have mercy on us.
Spirit, Comforter, we your people pray, have mercy on us.
Lord, our strength and our eternal salvation, have mercy on us.
Supreme and one God, mercifully grant us the gifts of life, and in your kindness, have mercy on us.
Source: The Sarum Missal in English, Part II, Alcuin Club Collections, No. XI,11th-15th centuries
Original (or similar text) in Latin:
Pater creator omnium tu theos ymon nostri pie eleyson .
Tibi laudes coniubilantes regum rex pie orainus te eleyson.
Laus uirtus pax et imperium cui est semper sine fine eleyson .
Christe rex unice patris almi nate coeternęt eleyson.
Qui perditum hominem saluasti de morte reddens uitę eleyson.
Ne pereant pascue oues tuę ihesu pastor bone eleyson .
Kirri soter agye supplices imas te exoramus eleyson.
Uirtus nostra domine atque salus uera in eternum eleyson.
Trine deus et une uite donat nobis tribue misertus nostrique tu digneris eleyson.