"O Roma felix"

O Roma felix, quæ tantorum principum
es purpurata pretioso sanguine,
non laude tua, sed ipsorum meritis
excellis omnem mundi pulchritudinem.

     Stanza 5 of the 6th (???)-century hymn "Aurea luce et decoro roseo" (earliest manuscript listed in CANTUS:  1000s/c. 1075).  "Aurea luce et decoro roseo" was for a time replaced by the incipit "Decora lux aeternitatis auream", but restored in the post-Vatican II Liturgia horarum (if not earlier).  In Connelly's edition of "Decora lux aeternitatis auream" it appears as follows:

O Roma felix, quae duorum principum
Es consecrata glorioso sanguine.
Horum cruore pupuata ceteras
Excellis orbis una pulchritudines.

Trans. Connelly:

How happy, Rome, your fortune in being dedicated to God in the Prince's noble blood; for clad in a robe dyed in purple with their blood, you far outstrip in beauty all else the world can show.

     But the original incipit "Aurea luce et decoro roseo" was restored to the post-Vatican II Lituria horarum:  Hymn, First Vespers (Evening Prayer I), Solemnity of Saints Peter and Paul, 29 June, Liturgia horarum.
     Still, "O Roma felix" was not original to "Aurea luce et decoro roseo", having been imported from the nth-century "hymnus de sancto Petro Pauloque" "Felix per omnes festum mundi cardines" (earliest manuscript listed in CANTUS:  c. 1075), where it was stanza number seven, and where, with its original order-of-the-lines and a fifth, it appears (in the properly critical edition ed. Milfull) as follows:

O Roma felix, que tantorum principum
es purpurata pretioso sanguine
excellis omnem mundi pulchritudinem
non laude tua, sed sanctorum meritis,
quos cruentatis jugulasti gladiis.

Trans. Milfull:

O happy Rome, you who are clothed in the purple of the precious blood of such great princes, you surpass all the beauty of the world not by your fame, but by the merits of your saints, whom you murdered with your bloodied swords.

Milfull:  "Cf. the poem O Roma nobilis (The Oxford Book of Medieval Latin Verse, ed. F. J. E. Raby (Oxford, 1959), p. 190)."

Bibliography:

• Connelly, Joseph.  Hymns of the Roman liturgy.  Westminster, MD:  The Newman Press, 1957.  Pp. 168-171.
• Julian, John, Ed.  Dictionary of hymnology.  London.  J. Murray, 1892.  P. 93.
• Milfull, Inge B.  Hymns of the Anglo-Saxon church:  a study and edition of the "Durham hymnal".  Cambridge:  Cambridge University Press, 1996.  Pp. 452 ff. (on "Felix per omnes festum mundi cardines").  Cf. pp. 332 ff. (on "Aurea luce et decore roseo", in which modern critical edition "O Roma felix" does not appear).
• Stevenson, Joseph.  Latin hymns of the Anglo-Saxon church, with an interlinear Anglo-Saxon gloss, derived chiefly from a manuscript of the eleventh century preserved in the library of the dean and chapter of Durham.  Durham:  George Andrews, [1851].  Pp. 160 ff.