Leonie Aviat was born on September 16, 1844, in Sezanne. Her parents were shopkeepers. She was baptized the day after her birth in a local church.
Leonie received her education at the convent school of the Visitation in Troyes. There she received religious education from Servant of God Marie de Sales Chappuis and her chaplain was Blessed Louis Brisson.
When she returned home, Leonie’s parents expected her to marry a rich man. She announced her intention to join a religious order, which did not please them. Leonie made a spiritual retreat to discern her future, but Brisson and Chappuis both advised her to wait.
After witnessing the poor living conditions of the men and women who worked in factories and textile mills, Brisson and Leonie established a new religious congregation, dedicating to helping them. In April 1866, Aviat, Brisson, and a former boarding school companion Lucie Caneut, founded the Oblate Sisters of St. Francis de Sales.
Leonie went on to establish parish schools, including a boarding school for girls in Paris. She also protected workers who had come from the rural areas to work in the cities, making sure they kept their jobs during the Franco-Prussian War.
In 1871, Leonie professed her vows, becoming the first Superior General of the congregation. She served two separate terms in office, during which time she is credited with curing a postulant’s abscessed heel bone with a relic of St. Francis de Sales. After her second term ended, she found herself at odds with the two subsequent Superior Generals, a trial she bore silently and patiently.
When Leonie was in Paris for the order’s General Chapter in 1893, she heard a voice telling her that she would be re-elected as Superior General. She was elected the next morning. The order moved its motherhouse to Italy a few years later.
The day after Christmas in 1913, Leonie fell ill. She received last rites on January 9, and died on January 10, 1914.
Leonie was named a Servant of God by Pope Pius XII in April 1957, and was made a Venerable in 1978. After a 14-year-old girl from Philadelphia was cured of a paralyzing spinal disease, Pope John Paul II canonized Aviat in 2001.