Saint Madeleine Sophie Barat (1779-1865) was a French nun, foundress of the Society of the Sacred Heart (RSCJ), dedicated to educating young girls and revealing the love of Christ's heart, with her life documented extensively through her numerous letters, which showcase her deep spirituality, growth as a leader, and dedication to her mission despite personal challenges and the changing world after the French Revolution. Her letters, though once edited for 'saintliness', reveal a lively, unguarded woman whose passion for education and faith inspired the spread of her order across continents, focusing on developing the minds and hearts of future Christian women.