He was a leading figure in the revival of the Catholic Church in France after the French Revolution, involved in founding three religious institutes as part of this effort.

He is one of the sons of Robert de Lamennais, a wealthy merchant who had recently received a coat of arms from the king, and Marie des Saudrais.

He was five years old when his mother died, and as a result, he and his younger brother were sent for education to an uncle, Robert des Saudrais, at La Chênaie, an estate near Saint-Malo.

The following year Lamennais helped the former rector of a secondary school previously run by the church, closed by the Revolution, to re-open the institution.

In addition to these other duties, he took an active role in the founding of the Congregation of St. Peter, dedicated to the administration of the diocesan seminary and of parish missions, having to act as its Superior General for a brief period.

One prelate, Bishop John Dubois of New York, was so impressed by Lamennais' dedication and capability after receiving help from him, that he appointed him vicar general for his own diocese in the United States.

[3] As he carried out his ministry, Lamennais became aware of a great problem of juvenile delinquency among the children of the working class, especially among the Breton population, who frequently had no access to education.

In November 1816, under the guidance of Lamennais, three young women formed a religious community dedicated to the education of the local youth and the care of orphans.

He initially sought the help of the Brothers of the Christian Schools, founded by John Baptist de la Salle to educate poor boys.

He was stymied, however, as the regulations of those Brothers forbade their working alone, while the mission he envisioned often needed only one teacher for an isolated location with a small student population.

Lamennais learned of the establishment of a small group of religious brothers by Gabriel Deshayes (1767-1841), pastor of Auray and vicar general of the Diocese of Vannes.

[5] They then made a spiritual retreat at Auray, at the end of which, on 15 September 1820, they took religious vows, through which the institute became formally established as the Brothers of Christian Instruction.

Félicité remained at La Chênaie and taught the younger members of the new congregation and worked to spell out the ideas of his long-cherished project of forming a community of priests thoroughly equipped for the pressing needs he foresaw for the future of the Catholic Church in France.

By the time of his death in December 1860, the brothers had 852 members serving throughout France and its far flung colonies in the world, from French Guiana to Senegal.