At age 15 Saint Genevieve became a nun and she knew well before that tender age that she wanted to devote her life to Christ. From an early age, Genevieve was able to prophesize the future. Her most famous foretelling was that the city of Paris would be invaded and destroyed.
When the Franks did invade Paris she was a pivotal force in organizing its defenses against the army. She also organized large prayer vigils that are believed to have saved the city from ruin.
Her visions also caused the church of Saint-Denis to be built. And during a horrible plague, her relics were walked through the city and the plague removed.
A powerful set of miracles for the faithful to remember and to be reminded that God works through us all.
Her memorial day is January 3rd. She is the patron saint of Paris, against plague and disasters.