Corpus Christi is a Latin Rite solemnity

Solemnity

A Solemnity of the Roman Catholic Church is a principal holy day in the liturgical calendar, usually commemorating an event in the life of Jesus, his mother Mary, or other important saints. The observance begins with the vigil on the evening before the actual date of the feast...

, now designated the solemnity of The Most Holy Body and Blood of Christ (Corpus Christi). It is also celebrated in some Anglican

Anglicanism

Anglicanism is a tradition within Christianity comprising churches with historical connections to the Church of England or similar beliefs, worship and church structures. The word Anglican originates in ecclesia anglicana, a medieval Latin phrase dating to at least 1246 that means the English...

, Lutheran

Lutheranism

Lutheranism is a major branch of Western Christianity that identifies with the theology of Martin Luther, a German reformer. Luther's efforts to reform the theology and practice of the church launched the Protestant Reformation...

 and Old Catholic Church

Old Catholic Church

The term Old Catholic Church is commonly used to describe a number of Ultrajectine Christian churches that originated with groups that split from the Roman Catholic Church over certain doctrines, most importantly that of Papal Infallibility...

es. Like Trinity Sunday

Trinity Sunday

Trinity Sunday is the first Sunday after Pentecost in the Western Christian liturgical calendar, and the Sunday of Pentecost in Eastern Christianity...

 and the Solemnity of Christ the King, it does not commemorate a particular event in Jesus

Jesus

Jesus of Nazareth , commonly referred to as Jesus Christ or simply as Jesus or Christ, is the central figure of Christianity...

' life. Instead it celebrates the Body and Blood of Christ really present in the Eucharist

Eucharist

The Eucharist , also called Holy Communion, the Sacrament of the Altar, the Blessed Sacrament, the Lord's Supper, and other names, is a Christian sacrament or ordinance...

. Its date is the Thursday after Trinity Sunday, but "where the Solemnity of the Most Holy Body and Blood of Christ is not a Holyday of Obligation, it is assigned to the Sunday after the Most Holy Trinity as its proper day".

At the end of the Mass, it is customary ìn many places to have a procession

Procession

A procession is an organized body of people advancing in a formal or ceremonial manner.-Procession elements:...

 of the Blessed Sacrament

Blessed Sacrament

The Blessed Sacrament, or the Body and Blood of Christ, is a devotional name used in the Roman Catholic Church, Eastern Catholic Churches, Old Catholic, Anglican, and Lutheran churches, to refer to the Host after it has been consecrated in the sacrament of the Eucharist...

, followed by Benediction of the Blessed Sacrament

Benediction of the Blessed Sacrament

Benediction of the Blessed Sacrament is a devotional ceremony celebrated within the Latin Rite of the Roman Catholic Church, as well as in some Anglican and Lutheran Churches, Liberal Catholic churches, Western Rite Orthodox churches, and Latinised Eastern Catholic Churches.Benediction of the...

.
The appearance of Corpus Christi as a feast in the Christian calendar was primarily due to the petitions of the thirteenth-century Augustinian nun

Nun

A nun is a woman who has taken vows committing her to live a spiritual life. She may be an ascetic who voluntarily chooses to leave mainstream society and live her life in prayer and contemplation in a monastery or convent...

 Juliana of Liège

Juliana of Liège

Saint Juliana of Liège was a religious woman and visionary from Retinnes in the Bishopric of Liège, now in Belgium. She was known in her community for her "capacious memory," her gift of prophecy, and religious devotion...

.