One of the most popular icons of art and tattoo art is the so-called Sacred Heart of Jesus, a mystical-religious representation with a heart-shaped lamp, surrounded by a crown of thorns and with a flame on the top, often coming out of the central upper hole.
Here’s some history: this iconography started at the end of the 17th century and more precisely between 1673 and 1675, when, in the convent of Paray-le-Monial, nun Margaret Maria Alacoque had a series of mystical visions that, after her death (in 1690) were used for her canonization process.
Nun Alacocque, in her memories, described the second vision when: “the sacred Heart appeared on a throne of flames, brighter than the sun and transparent as crystal, surrounded by a crown of thorns representing the injuries caused by our sins and with a cross on top, because from when it was formed, it was already filled with bitterness…”
This series of prophetic visions brought Margaret Maria Alacoque to become an apostle of a movement whose scope was to transfer the worshipping of devotees to the Sacred Heart, source of all feelings that God gave us and of all the favors he did for us. Shortly, the cult of the Sacred Heart became one of the most popular in Christian Europe, thanks to the healing practices of many followers (The Sacred Heart still today is considered an object to worship by those who have been healed from an illness), so much that the Catholic religious hierarchy was concerned about the fact that in reality it was a sort of idolatry.
What worried the Catholic clergy in fact was the continuous artistic representation of the Sacred Heart in itself, not combined with the figure of Jesus or of the Virgin Mary. Especially among the poorest classes, the worship of the Sacred Heart was so strong that enormous churches were built dedicated to it and the religious orders with these words in their name increased incredibly between the 19th and 20th centuries.