To trace Île Saint-Bernard’s rich history, it is necessary to go back 4,000 years in time, when Aboriginal communities occupied the land. Several archeological digs over the years have confirmed that a stopover on the island was highly appreciated by these occupants.

Several centuries later, in 1673, Île Saint-Bernard welcomed its first seigneur, Sieur Charles Lemoyne de Longueuil. He was responsible for the construction of the first manor house, a wooden fortification with a chapel, and a windmill. As the years came and went, so did a succession of seigneurs.

In 1765, Marguerite d’Youville, the founder of the Sisters of Charity of Montréal, better known as the Grey Nuns, acquired the seigneury of Châteauguay and became its last “seigneuresse.” For over 200 years, the Grey Nuns lived on the island and protected the land. They planted an orchard, set up a small dairy farm and grew wheat, barley, oats, buckwheat and vegetables. Since the Grey Nuns believed in “protecting all life,” it was possible to preserve an exceptional natural area, the Refuge faunique Marguerite-D’Youville (wildlife sanctuary). It is protected in perpetuity.