Sarum Kyrie eleison. No. 5.

V. Kyrie Rex Splendens Celi Arce Salue 
On the Feast of St. Michael and All Angels especially.

Lord, King of glory in the fortress of heaven, hail forevermore, and in your loving-kindness, have mercy on us.

The chanting hosts of cherubim proclaim your praise continually, have mercy on us.

The companies of seraphim on high shout to each other in your praise, have mercy on us.

Christ, King enthroned on high, whom the ranks of the angels sing in endless praise, have mercy on us.

Christ, whom the one only Church throughout the whole world sings out, sun and moon, stars, earth, sea: and to whom they evermore do service, have mercy on us.

All the saints, heirs of the glorious eternal kingdom, triumphantly proclaim you in noble strains, have mercy on us.

Gracious offspring of the loving virgin Mary, King of kings, blessed Redeemer, you ransomed us from the power of death by your own blood, have mercy on us.

Most illustrious, unbegotten,  begotten already without beginning, and without effort excelling all things, have mercy on us.

Sun of brilliant glory, dispenser of justice, when you judge all nations, we earnestly pray, in pity, have mercy on us.

Source: The Sarum Missal in English, Part II, Alcuin Club Collections, No. XI

Original in Latin:

Kyrie rex  splendens celi arce salue iugiter et clemens plebi tue semper
ymnidice quem turme cherubin laude perhenniter proclamant incessanter nobis eleyson.
Insigniter caterue precelse et quibus seraphin respondent te  laudantes nostri eleyson.
Christe rex altithrone ordines angelorum nouem quem laudant incessanter pulchre dignare seruis tuis semper eleyson .
Christe quem toto orbe unica ecclesia ymnizat sol et luna astra tellus mare cui et famulantur semper eleyson. ‘
Ipsi idem inclite patrie perpetue heredes sancti omnes digno carmine pro clamant quem ouanter nobis eleyson.
Virginis pie marie o alma proles rex regum benedicte redemptor cruore mercatis  proprio mortis ex potestate semper eleyson .
Insignissime ingenite o genite origine iam expers et fine uirtute excellens omniacaterue huic tue clemens eleyson.
acaterue huic tue clemens eleyson.
Limpidissime glorie sol iusticie arbiter omnes gentes districte dum iudices turme obnixe precamur nunc astanti clemens eleyson.