
The feast originated in the 13th century:
- St. Juliana of Liège: Inspired by visions she received from a young age, St. Juliana advocated for a special feast day dedicated solely to the Eucharist, separate from Holy Thursday.
- Bishop Robert de Thorete: The Bishop of Liège instituted the feast for his diocese in 1246.
- Miracle of Bolsena (c. 1263): A Bohemian priest doubting the Real Presence allegedly witnessed the Host bleed during Mass in Bolsena, Italy. This event strengthened calls for the feast.
- Pope Urban IV: Influenced by St. Juliana and the Miracle of Bolsena, Pope Urban IV instituted the Solemnity of Corpus Christi for the entire Latin Church in 1264 with the papal bull *Transiturus de hoc mundo*.
- St. Thomas Aquinas: Commissioned by Pope Urban IV, Aquinas composed liturgical texts for the feast, including famous hymns like *Pange Lingua* (whose last two stanzas form the *Tantum Ergo*) and *Lauda Sion*.