Corpus Christi (Latin: "Body of Christ") is a Catholic feast celebrating the Real Presence of the Body and Blood of Jesus Christ in the Eucharist. It falls on the Thursday after Trinity Sunday (60 days after Easter).
Established by Pope Urban IV in 1264. The feast was promoted by St. Juliana of Liège, who had a vision urging its institution. Composer Thomas Aquinas wrote much of the liturgy.
Eucharistic processions through streets, sometimes featuring elaborate flower carpets ("alfombras de flores" in Latin America). Children make their First Communion around Corpus Christi in many places. Outdoor altars are built along procession routes.
Public holiday in Austria, Switzerland (most cantons), Portugal, Brazil, Colombia, Poland, Croatia, Germany (in several Länder), and other Catholic-majority countries. In some places it's observed on the following Sunday.