The sequence for Corpus Christi is over 750 years old
Sequences are special readings inserted between the Second Reading and the Gospel on certain feast days. The Roman Rite normally follows a fixed rhythm, but sequences add a poetic summary of the day's theme. For Corpus Christi, St. Thomas Aquinas wrote a sequence at the behest of Pope Urban IV to emphasize the Eucharist and Jesus’ Real Presence. The sequence serves to remind the faithful of the special nature of the feast. The article explains the historical and liturgical context of the sequence and its purpose.
4 months ago
The Catholic Church’s feast of Corpus Christi includes a special hymn called a sequence, “Lauda Sion,” which was composed by St Thomas Aquinas in the mid‑13th century and remains in use today, making it more than 750 years old1.
A sequence is a poetic chant placed between the Second Reading and the Gospel on certain solemnities.
It offers a concise, lyrical summary of the day’s spiritual theme and breaks the usual rhythm of the Mass, highlighting the feast’s importance1.
Pope Urban IV commissioned St Thomas Aquinas to write a sequence for the newly established feast of Corpus Christi.
Aquinas completed Lauda Sion around 1264, and it is one of the few medieval sequences retained in the modern Roman Rite1.
The hymn celebrates the institution of the Eucharist and the Real Presence of Christ.
Its verses weave biblical typology (Isaac, the Paschal Lamb, manna) with the mystery of bread becoming Christ’s body and wine becoming his blood.
The poem stresses faith in the unseen, the unity of the faithful through the sacrament, and the triumph of the new covenant over the old rites1.
During the Mass of Corpus Christi, “Lauda Sion” is sung after the Second Reading, preceding the Gospel.
Its continued use connects contemporary worshippers with a medieval theological masterpiece and reinforces the feast’s focus on Eucharistic thanksgiving1.*
Corpus Christi sequence exemplifies medieval Eucharistic theology
The Corpus Christi sequence (most famously Lauda Sion Salvatorem, and in the same liturgical tradition Sacris solemniis) gathers medieval Eucharistic theology into memorable prayer: it treats the Eucharist as Christ’s sacrificial presence, shows how Holy Orders is ordered to Eucharistic consecration, and reads the Eucharist as the Church’s fulfillment of God’s covenants through Scripture’s typology.
A defining medieval instinct—already deeply rooted in the Church’s tradition—is that the Eucharist is not merely a memory of something past, but the real continuation and making-present of Christ’s saving sacrifice “once for all,” offered in a sacramental mode.
Pope John Paul II frames this precisely for Corpus Christi by moving from Christ’s priesthood (rooted in Psalm 109) to the Eucharist’s sacrificial character. Christ is “priest forever” and “obtained dominion” by offering himself “in sacrifice,” i.e., “sacrifice of body and blood,” “triumph” by the Cross.
Then the homily explains the distinctive Eucharistic mode: the same sacrifice is “completed… for the Church under the species of bread and wine” the day before Passover. This is why Christ becomes “priest… forever…” for the Church by means of the sacrifice offered “after the manner of Melchizedek.”
So the medieval sequence’s “theological poetry” exemplifies a key doctrine: the Cross remains the source, and the Eucharist is the sacramental making-present of that saving mystery—so that “the Church lives daily” from it.
Medieval Eucharistic theology also tends to be ecclesial and priestly: Corpus Christi is not only about adoration; it is about the consecrating priesthood that brings the sacrament to the faithful.
A recent scholarly treatment of Aquinas’s Corpus Christi liturgy highlights exactly this synthesis. It notes that magisterial teaching is clear that Christ instituted the Eucharist as the memorial of his death and Resurrection and “thereby he constituted them priests of the New Testament” (CCC 1337).
Within Aquinas’s development, the Eucharist appears as the “most noble and perfect” sacrament, and the power of Order is considered principally with reference to it. This yields the ordered structure: the priest’s consecratory ministry is the foundation that other sacramental powers serve.
Put simply in medieval sacramental logic: there is no “Eucharist without priesthood.” The sequence’s theological horizon therefore tends to make you feel the unity between (1) Christ’s priesthood and (2) the Church’s ordained ministry that makes the Eucharist present.
Another medieval hallmark is covenantal reading: Scripture’s patterns (sacrifice, priesthood, meal, temple) are seen as moving toward fulfillment in Christ, and the Eucharist is where that fulfillment is enacted sacramentally.
Pope John Paul II explicitly presents the Eucharist in covenant language: Christ “instituited the new alliance of God with man in his body and blood,” and “no one can repeat” his bloody sacrifice, but he “instituted… the same sacrifice” for the Church “under the species of bread and wine.”
Meanwhile, a covenant-theology perspective (drawing on Cardinal Ratzinger) underscores that biblical “covenant” is not a simplistic one-to-one label; Scripture can speak of covenants in plural while still relating them to the covenant of Christ—especially the Abrahamic and Mosaic covenants.
Schenk’s study on medieval theology then helps you see how medieval authors handle fulfillment without flattening history: the notion of “fulfillment” is “extremely complex,” and it can be distorted if one insists unilaterally on either continuity or discontinuity. In other words, medieval Eucharistic poetry aims at a dynamic “both/and”: continuity with God’s promises, and real newness in Christ’s sacrifice.
The Corpus Christi sequence also exemplifies a medieval (and patristic) hermeneutic: Scripture’s events and persons function as types that find their depth in Christ.
John Chrysostom expresses this type/fulfillment logic with clarity: he distinguishes “type” from mere surface history, saying that what appears “on the face of it” also “announces somewhat farther,” which is why it is called an allegory.
That same instinct is what makes Eucharistic liturgy “read” the Old through the New—not in a reductionist way, but as a divinely intended pattern that reaches its meaning in Christ’s Paschal gift.
Finally, the very form of a sequence—poetic proclamation meant for chant—fits medieval theology’s confidence that one can speak truly of divine realities without pretending that human concepts can “capture” God exhaustively.
Schenk describes Aquinas’s approach as a “discipline of ambiguity,” rooted in analogical language: there is an unavoidable tension between what we affirm about God and what we must deny about the way we imagine God based on created categories (“significatio” and “modus significandi”).
This matters because Corpus Christi hymnody is designed to be doctrinally precise yet contemplative—bright, but diffuse, as the “light of analogy” is described. The result is a theology that educates the mind and enlarges worship: the sequence becomes a kind of catechism in song.
In sum: the Corpus Christi sequence exemplifies medieval Eucharistic theology by combining (1) sacrificial Christology (the one sacrifice present under bread and wine), (2) ordained-ministry Christology (Order is ordered to consecration), and (3) covenantal, typological fulfillment (Scripture’s patterns find their truth in the Eucharist), all expressed through a medieval method of analogical, liturgical language.