St. Margaret Mary Alacoque was a mystic and leader of the devotion to the Sacred Heart of Jesus.

St. Margaret Mary Alacoque was born on July 22, 1647 in L’Haute-cour, in Burgundy, France. When her father, Claude Alacoque, died, Margaret Mary was sent to the Poor Clare school at Charolles. There she was bedridden for five years with rheumatic fever, regaining her health at the age of fifteen.

In 1671, Margaret Mary entered the Visitation convent at Paray-le-Monial and was professed the following year. She experienced visions, and on December 27, 1673, she began having revelations that lasted for eighteen months.

She was informed by Christ that she was his instrument in spreading devotion to his Sacred Heart. After being rebuffed by her superior and local churchmen, Margaret Mary’s visions were declared genuine by St. Claude de la Colombiere. In 1683, she was given positions in her community and witnessed the spread of devotion to the Sacred Heart. She died at Paray-le-Monial on October 17, 1690 and was canonized in 1920.

St. Margaret Mary Alacoque is called a “Saint of the Sacred Heart.” The devotion was approved by Pope Clement XIII in 1765.