June is known as the month of the Sacred Heart of Jesus most simply because the solemnity of the Sacred Heart is celebrated during this month. This year, the solemnity falls on June 16. The date changes each year because it is celebrated on the Friday after the Corpus Christi octave, or the Friday after the second Sunday after Pentecost.

However, other reasons exist as to why June is dedicated to the Sacred Heart.

The feast dates back to 1673, when a French nun who belonged to the Order of the Visitation of Holy Mary (Visitandines) in eastern France began to receive visions about the Sacred Heart.

Jesus appeared to Sister Margaret Mary Alacoque and revealed ways to venerate his Sacred Heart and explained the immense love he has for humanity, appearing with his heart visible outside his chest, on fire, and surrounded by a crown of thorns.

These different ways include partaking in a holy hour on Thursdays and the reception of the Eucharist on the first Friday of every month.

Jesus told Sister Margaret Mary: “My Sacred Heart is so intense in its love for men, and for you in particular, that not being able to contain within it the flames of its ardent charity, they must be transmitted through all means.”

These visions continued for 18 months.

On June 16, 1675, Jesus told Sister Margaret Mary to promote a feast that honored his Sacred Heart. He also gave Sister Margaret Mary 12 promises made to all who venerate and promote the devotion of the Sacred Heart.

He said: “I ask of you that the Friday after the octave of Corpus Christi be set apart for a special feast to honor my heart, by communicating on that day, and making reparation to it by a solemn act, in order to make amends for the indignities which it has received during the time it has been exposed on the altars. I promise you that my heart shall expand itself to shed in abundance the influence of its divine love upon those who shall thus honor it, and cause it to be honored.”

Sister Margaret Mary died in 1690 and was canonized by Pope Benedict XV on May 13, 1920.

The Vatican was hesitant to declare a feast to the Sacred Heart, but as the devotion spread throughout France, the Vatican granted the feast of the Sacred Heart of Jesus to France in 1765.

In 1856, Pope Pius IX designated the Friday following the feast of Corpus Christi as the feast of the Sacred Heart for the universal Church. Ever since, the month of June has been devoted to the Sacred Heart of Jesus and his immense love for us all.

On the current calendar, the feast of the Sacred Heart of Jesus is a solemnity, the highest-ranking feast in the liturgical calendar, although it is not a holy day of obligation.

These are the promises the Sacred Heart of Jesus made to St. Margaret Mary Alacoque:

1. I will give them all the graces necessary for their state of life.
2. I will give peace in their families.
3. I will console them in all their troubles.
4. I will be their refuge in life and especially in death.
5. I will abundantly bless all their undertakings.
6. Sinners shall find in my heart the source and infinite ocean of mercy.
7. Tepid souls shall become fervent.
8. Fervent souls shall rise speedily to great perfection.
9. I will bless those places wherein the image of my Sacred Heart shall be exposed and venerated.
10. I will give to priests the power to touch the most hardened hearts.
11. Persons who propagate this devotion shall have their names eternally written in my heart.
12. In the excess of the mercy of my heart, I promise you that my all-powerful love will grant to all those who will receive Communion on the first Fridays, for nine consecutive months, the grace of final repentance: they will not die in my displeasure, nor without receiving the sacraments; and my heart will be their secure refuge in that last hour.