Born in La Flèche (France), on March 18, 1597, he is the younger son of Jérôme Le Royer, first seigneur of La Dauversière, a local tax collector, and of Renée Oudin. He studies at the Jesuit College in La Flèche and wishes to enter the orders. But upon the death of his father in 1619, he inherits the estate of “La Dauversière”, whence comes the title attached to his name, and his father’s government post and so follows in his father’s footsteps as a tax collector.
This job does not diminish his attachment to the Church and, in 1630, together with his wife and his children Le Royer consecrates himself to the Holy Family. He dreams of founding a religious congregation of young women for the service of the poor and the sick – project that will become reality, in 1636, with the foundation of the Confrérie de Saint-Joseph, at the origin of the Institut des Religieuses Hospitalières de Saint-Joseph, and with the renovation of the chaplaincy of Sainte-Marguerite that he transforms in Hotel-Dieu.
Le Royer then turns to another dream he has, that of establishing a mission in New France to evangelize the Indians. In 1639 he presents his project to Father Charles Lalemant, in charge of the Jesuit missions in Canada, and to the French chancellor, together with Jean-Jacques Olier, the founder of the Séminaire de Saint-Sulpice, who shares the same dream. Together they found the Société Notre-Dame de Montréal that in 1640 buys the island of Montréal. Le Royer is in charge of raising funds and recruiting colons for the new mission. The Society sponsors Paul Chomedey de Maisonneuve and Jeanne Mance, a lay woman, to go found Ville Marie and establish a hospital, which will become the Hotel-Dieu of Montreal, to care for the poor.
The first colons leave in 1641 and found the city on May 17, 1642. Le Royer continues to recruit French colons for the mission, who set sail from La Rochelle for Ville-Marie. As he returns home from La Rochelle he gets sick and dies on November 6, 1659.
He was declared venerable by Pope Benedict XVI on July 6, 2007.
