Louis Gaston was born on 25 August 1825 in Pointe-à-Pitre (Guadeloupe), and came to France in 1832, where he studied for the military, following in his father's footsteps.

Appointed general of the army corps at the age of 45, he led the heroic charge of Loigny under the protection of the banner of the Sacred Heart, embroidered by Visitation nuns of Paray le Monial.

Seriously injured in this battle, the Blessed Virgin Mary appeared to the General, assuring him that all was not lost; France would survive.

He showed that the martial spirits that are so often admired in soldiers of the warrior class do not mutually exclude a strong faith life.

De Sonis shared many similar attributes with a current day exemplar of another great Catholic warrior—Colonel John Ripley.