The feast of the Sacred Heart of Jesus is celebrated every year 19 days after Pentecost (which is always a Friday).
Here are 6 things you probably didn’t know about the devotion:
1) It dates back at least to the 12th century
Though it’s impossible to say where the devotion originated from exactly, evidence for it first appears around the time of the early Franciscans in the 12th century.
Following the lead of St. Francis of Assisi, the early Franciscans had a particular devotion to the wounds of Jesus, and this included his heart pierced with a lance during his crucifixion.
2) The first hymn to the Sacred Heart is from the 13th century
The early 13th century Norbertine Bl. Herman Joseph composed a hymn called “Summi Regis Cor Aveto,” which means “Heart of the highest king, I greet You” (these are its first words).
3) Its feast was first celebrated in the 17th century
St. John Eudes, who founded the Congregation of Jesus and Mary, wrote a set of prayers for an Office and Mass for a feast of the Sacred Heart of Jesus. These prayers continued to be used as the feast spread throughout the world.
In the 19th century, Pope Leo XIII honored him with the title “Author of the Liturgical Worship of the Sacred Heart of Jesus and Holy Heart of Mary.”
4) The details of the modern devotion were revealed to a 17th century nun
St. Margaret Mary Alacoque was a nun in the Order of the Visitation of Holy Mary. She claims to have experienced a number of visions of Jesus over an 18 month period in the mid-17th century.
Jesus, she claims, gave her precise instructions describing the full, modern devotion to the Sacred Heart of Jesus. This includes the reception of the Eucharist on first Fridays, Eucharistic adoration on Thursdays, and celebration of the feast of the Sacred Heart of Jesus.
After the final vision, she reported all that she had seen to a priest friend, who encouraged her to write an account, which she did. Her book was circulated throughout France and England and was widely read.
5) A 19th century nun sent letters to Pope Leo XIII requesting him to consecrate the world to the Sacred Heart – and he did
Bl. Mary of the Divine Heart, a nun of the Congregation of Our Lady of Charity of the Good Shepherd, claimed in the late 19th century to have experienced a number of visions of Jesus. In one of the last ones, she said Jesus told her to write letters to Pope Leo XIII asking him to consecrate the whole world to the Sacred Heart of Jesus.
When Leo XIII received her first letter, he was skeptical of her claims and dismissed it. A few months later, she sent another one. This time, she also mentioned the Pope’s ill health and said Christ had assured her that he would live at least until he performed the consecration. A few months later, he promulgated an encyclical saying that the whole world would be consecrated to the Sacred Heart of Jesus a month later on Sunday, June 11th, 1899.
Bl. Mary of the Divine Heart died three days before the consecration on Friday, June 8th, 1899 – which was the feast of the Sacred Heart of Jesus.
6) Even some Eastern Catholics have taken up the practice
But the practice is controversial, with some critics calling it Latinisation (in which Eastern Christianity is unduly influenced by the traditions of the West).
Many Eastern Orthodox Christians are also against the devotion due to concerns that it could imply a heretic Christology. In response to these criticisms, Pope Pius XII argued in 1956 that the Sacred Heart is venerated only insofar as it belongs to the Divine Person God the Son, and so is a legitimate devotion.