Pierre Mongeau was born circa 1620 in Dompierre-sur-Mer, Charente-Maritime, France. Son of Jacques and Jeanne Clémenceau, he married Louise Dubois, of unknown parentage, circa 1645 in Dompierre-sur-Mer. Their 6 children were born in France. He settled in the country in 1662 with his family. He is known to be a carpenter specialized in large framing work and a ploughman. He died on June 17, 1663 and he was buried the next day in Quebec.
Jacques Mongeau was born on March 28, 1649 and was baptized the next day in Dompierre-sur-Mer, Charente-Maritime, France. Son of Pierre and Louise Dubois, he married Catherine Millot, daughter of Jacques and Jeanne Hébert, on March 1, 1685 in Montreal. They had 6 children. He came to New France with his parents in 1662 and lived in Quebec, Bastiscan and, after his wedding, in Varennes. In 1678, in order to avoid a trial, he and two other individuals compensated a man they had mistreated. Circa 1683, it made the fur trade, activity that he continued after his marriage. He died before April 17, 1698 in a place which remains unknown.
Jean-Baptiste Mongeau was born and baptized on August 7, 1661 in Dompierre-sur-Mer, Charente-Maritime, France. Son of Pierre and Louise Dubois, he married Elisabeth Bonnodeau, daughter of Louis and Claude de Laval, on February 14, 1691 in Quebec. From this union were born 5 children. He came to New France with his parents in 1662. In 1690 he lived in Varennes. The same year he went to Orange. In August 1691, he committed to work for one year for the commander of Fort St-Louis in Detroit. 1693, He travelled to the Outaouais region for the fur trade. He was buried in Montreal on August 6, 1708.