Rex Christe, factor omnium. St. Gregory the Great. [Passiontide.] This is one of the eight hymns accepted in the Benedictine edition of Gregory's Opera (Paris, 1705, vol. iii. col. 879), as his genuine productions. It is found in a manuscript of the 11th century, in the British Museum (Harl. 2981 f. 240); in a manuscript of the 12th cent, in the Bodleian (Liturg. Misc. 297 f, 309); in three manuscipts of the 11th century, at St. Gall (Nob, 387, 313, 314), and others. In mediaeval times it was often used at the Tenebrae service on Good Friday, but does not seem to have been received into the more important Breviaries. It long survived in its original form in the Lutheran Church, and is e.g. in the Dresden Gesang-Buch, 1748, p. 991, as one of "Certain Latin hymns as they are sung from time to time at week-day sermons in the Holy Cross Church, at the beginning of Divine service." The text is found in Daniel, i., No. 151; Bässler, No. 58; Königsfeld, i. p. 72, and others. Translated as:—
0 Christ! our King, Creator, Lord. By Ray Palmer, in the Andover Sabbath Hymn Book, 1858, No. 336.
Other translations are:—
1. O Christ our King, Who all hast made. W. J. Copeland, 1848.
2. O Christ our King, by Whom were framed. J. D. Chambers, 1852 and 1857.
3. Thou King anointed, at Whose word. Rev. James Inglis, N. York, 1868, in Schaff’s Christ in Song, 1809.
4. O Thou by Whom the worlds were made. D. T. Morgan. 1880. [Rev. James Mearns, M.A.]
--John Julian, Dictionary of Hymnology (1907)