The following is a juxtaposition of part of an ancient text known as
"de Sacramentis", usually attributed to St. Ambrose of Milan, and the
canon of the traditional Catholic Mass of the Roman rite.  The
conclusion from this comparison is that the central part of the
traditional Roman canon was already fairly well in place by sometime
in the late 4th century.

Taken from "The Mass of the Western Rites", by the Right Reverend Dom
Fernand Cabrol, Abbot of Farnborough, 1934, without permission.
Excerpted from Chapter VI: THE MASS AT ROME, FROM THE FIFTH TO THE
SEVENTH CENTURIES.  The paragraph at the end is from the book, not me.

Sorry about the long lines.

Joe Buehler

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TEXT OF DE SACRAMENTIS          ROMAN CANON                     ROMAN CANON
(about 400 AD)                  (1962 AD)                       (English translation)

                                Te igitur ...                   (omitted here)
                                Memento Domine ...
                                Communicantes ...
                                Hanc igitur oblationem ...

Fac nobis (inquit sacerdos),    Quam oblationem tu Deus, in     Do thou, O God, deign to
hanc oblationem ascriptam,      omnibus, quaesumus,             bless what we offer, and
ratam, rationabilem,            benedictam, adscriptam,         make it approved,
acceptabilem, quod figura       ratam, rationabilem,            effective, right, and
est corporis et sanguinis       acceptabilemque facere          wholly pleasing in every
Jesu Christi.                   digneris: ut nobis corpus et    way, that it may become
                                sanguis fiat dilectissimi       for our good, the Body
                                Filii tui Domini nostri Jesu    and Blood of Thy dearly
                                Christi.                        beloved Son, Jesus Christ
                                                                our Lord.

Qui pridie quam pateretur,      Qui pridie quam pateretur,      Who, the day before He
in sanctis manibus suis         accepit panem in sanctas ac     suffered, took bread into
accepit panem, respexit in      venerabiles manus suas: et      His holy and venerable
caelum ad te, sancte Pater      elevatis oculis in ccelum,      hands, and having raised
omnipotens, aeterne Deus,       ad Te Deum Patrem suum          His eyes to Heaven, unto
Gratias agens, benedixit,       omnipotentem, tibi gratias      Thee, O God, His Almighty
fregit, fractum quae            agens, benedixit, fregit,       Father, giving thanks to
apostolis suis et discipulis    deditque discipulis suis        Thee, He blessed it, broke
suis tradidit dicens:           dicens: accipite et             it, and gave it to His
accipite et edite ex hoc        manducate ex hoc omnes: hoc     disciples, saying: Take ye
omnes: hoc est enim corpus      est enim corpus meum.           all and eat of this:
meum, quod pro multis                                           For this is my Body.
confringetur.

Similiter etiam calicem         Simili modo postquam            In like manner, when the
postquam caenatum est,          caenatum est, accipiens et      supper was done, taking
pridie quam pateretur,          hunc praeclarum calicem in      also this goodly chalice
accepit, respexit in            sanctas ac venerabiles manus    into His holy and
caelum ad te, sancte pater      suas item tibi gratias          venerable hands, again
omnipotens, aeterne Deus,       agens, benedixit deditque       giving thanks to Thee,
gratias agens, benedixit,       discipulis suis, dicens:        He blessed it, and gave it
apostolis suis et discipulis    accipite et bibite ex eo        to His disciples, saying:
suis tradidit, dicens:          omnes: Hic est enim calix       Take ye all, and drink of
accipite et bibite ex hoc       sanguinis mei, novi et          this: For this is the
omnes: hic est enim sanguis     aeterni testamenti:             Chalice of my Blood of the
meus.                           mysterium fidei; qui pro        new and eternal covenant;
                                vobis et pro multis             the mystery of faith,
                                effundetur in remissionem       which shall be shed for
                                peccatorum.                     you and for many unto the
                                                                forgiveness of sins.

                                Haec quotiescumque feceritis    As often as you shall do
                                in mei memoriam facietis.       these things, in memory of
                                                                Me shall you do them.

Ergo memores gloriosissimae     Unde et memores, Domine, nos    Mindful, therefore, O
ejus passionis et ab inferis    servi tui, sed et plebs tua     Lord, not only of the
resurrectionis, in caelum       sancta, ejusdem Christi         blessed Passion of the
ascensionis, offerimus tibi     Filii tui Domini nostri, tam    same Christ, Thy Son, our
hanc immaculatam hostiam,       beatae passionis necnon et      Lord, but also of His
hunc panem sanctum et           ab inferis resurrectionis,      resurrection from the
calicem vitae aeternae;         sed et in caelos gloriosae      dead, and finally His
                                ascensionis: offerimus          glorious ascension into
                                praeclarae majestati tuae de    Heaven, we, Thy ministers,
                                tuis donis ac datis, hostiam    as also Thy holy people,
                                puram, hostiam sanctam,         offer unto Thy supreme
                                hostiam immaculatam, Panem      majesty, of the gifts
                                sanctum vitae aeternae, et      bestowed upon us, the
                                Calicem salutis perpetuae.      pure Victim, the holy
                                                                Victim, the all-perfect
                                                                Victim: the holy Bread of
                                                                life eternal and the
                                                                Chalice of unending
                                                                salvation.

et petimus et precamur, ut      Supra quae propitio ac          And this do Thou deign to
hanc oblationem suscipias in    sereno vultu respicere          regard with gracious and
sublimi altari tuo per manus    digneris: et accepta habere,    kindly attention and hold
angelorum tuorum sicut          sicuti accepta, habere          acceptable, as Thou didst
suscipere dignatus es munera    dignatus es munera pueri tui    deign to accept the
pueri tui justi Abel et         justi Abel, et sacrificium      offerings of Abel, Thy
sacrificium patriarchae         patriarchae nostri Abrahae,     just servant, and the
nostri Abrahae et quod tibi     et quod tibi obtulit summus     sacrifice of Abraham our
obtulit summus sacerdos         sacerdos tuus Melchisedech      patriarch, and that which
Melchisedech.                   sanctum sacrificium,            Thy chief priest
                                immaculatam hostiam.            Melchisedech offered unto
                                                                Thee, a holy sacrifice and
                                                                a spotless victim.

                                Supplices te rogamus,           Most humbly we implore
                                omnipotens Deus: jube haec      Thee, almighty God, bid
                                perferri per manus sancti       these offerings to be
                                Angeli tui in sublime altare    brought by the hands of
                                tuum in conspectu divinae       Thy holy angel unto Thy
                                majestatis tuae: etc.           altar above; before the
                                                                face of Thy Divine
                                                                Majesty; etc.