Vexilla Regis was written by Venantius Fortunatus (530-609) and is considered one of the greatest hymns of the liturgy. Fortunatus wrote it in honor of the arrival of a large relic of the True Cross which had been sent to Queen Radegunda by the Emperor Justin II and his Empress Sophia. Queen Radegunda had retired to a convent she had built near Poitiers and was seeking out relics for the church there. To help celebrate the arrival of the relic, the Queen asked Fortunatus to write a hymn for the procession of the relic to the church.
The hymn has, thus, a strong connection with the Cross and is fittingly sung at Vespers from Passion Sunday to Holy Thursday and on the Feast of the Triumph of the Cross. The hymn was also formerly sung on Good Friday when the Blessed Sacrament is taken from the repository to the altar. Click here for the full text of Fortunatus’ hymn.