The Roman office assigned Vexilla Regis to Vespers in Passiontide, the last two weeks of Lent, when the church's attention closes on the cross, and to the feasts of the Holy Cross, and it is sung on Good Friday as the reserved sacrament is carried to the altar, the banners of the king advancing at the rite's darkest hour. Its military imagery gave it a second, rougher history, the hymn of the standard was adopted as a crusading song, and vexilla regis passed into the vocabulary of Christian armies, a reminder that liturgical poetry does not control its own reception. Dante paid the hymn literature's strangest compliment.
The final canto of the Inferno opens Vexilla regis prodeunt inferni, the banners of the king of hell advance, announcing Satan by parodying the hymn every reader would know, the frozen counter procession at the bottom of the world. Composers have returned to the text steadily, in chant, in Renaissance polyphony, and notably in Bruckner's late motet, while Liszt built a movement of his Via Crucis on it, and the hymn's stanzas, lightly revised over the centuries and restored in modern books, remain in the Liturgy of the Hours, so that a processional written for one afternoon in sixth century Poitiers is still doing annual duty wherever the Latin rite keeps Passiontide.