Saint-Denis-sur-Sarthon is a small village located 15 kilometers from Alençon where Zélie Guérin's father, Isidore Guérin, ended his military career as a gendarme on foot and then on horseback. The Guérin family left this village when the father retired to live in Alençon, at 36 rue Saint-Blaise, which would become the birthplace of Saint Thérèse.
It was in Saint-Denis-sur-Sarthon that Zélie was baptized and lived until the age of 13. On the other hand, she was not born there, since it was the neighboring village of Gandelain that saw her born.
