The devotion arose in the twelfth century. While theologians such as St. Bonaventure addressed the topic, it was propagated primarily through the experiences and writings of mystics such as St. Mechtilde of Magdeburg, Julian of Norwich and St. Catherine of Siena. Devotion to the Sacred Heart of Jesus consists primarily in giving attention to the inexhaustible source of mercy and loved poured out for us by God through Jesus Christ.
The first feast of the Sacred Heart was celebrated on August 31, 1670, in Rennes, France through the efforts of Fr. Jean Eudes. From Rennes, the devotion spread but it took the visions of St. Margaret Mary Alacoque for the devotion to become universal. A Visitandine nun, St. Margaret Mary Alacoque, experienced visions of the Sacred Heart at Paray-le-Monial and received a set of twelve promises that would exert a strong influence on popular Catholic piety and devotion to the Sacred Heart.
Liturgical observance of the feast of the Sacred Heart was authorized by the Church in 1765, and then extended by Popes Pius IX, Leo XIII and Pius XI. In response to the visions of Sister Droste-Vishering, Leo XIII, in 1899, consecrated the whole world to the Sacred Heart of Jesus. In the renewed liturgy, the feast is celebrated as a solemnity on Friday of the second week after Pentecost. Devotion to the Heart of Jesus is not an exclusively Catholic one. English Puritan theologians such as Isaac Ambrose, Richard Baxter and Thomas Goodwin wrote about it.