Thou King of saints.@Revelation 15:3

Unknown author, probably 6th Century (Rex gloriose martyrum); translated from Latin to English by Richard F. Littledale and others.

Rex Gloriose French church melody (🔊 pdf nwc).

O glorious King of martyr hosts,
Thou crown that each confessor boasts,
Who leadest to celestial day
The saints who cast earth’s joys away;

Thine ear in mercy, Savior, lend,
While unto Thee our prayers ascend;
And as we count their triumphs won,
Forgive the sins that we have done.

Martyrs in Thee their triumph gain,
Confessors grace from Thee obtain;
We sinners humbly seek to Thee,
From sin’s offense to set us free.

All laud to God the Father be,
All praise, eternal Son, to Thee;
All glory, as is ever meet,
To God the holy Paraclete.