 He was born in Arthabaska, Quebec in 1880, the son of Joseph Lavergne and Émilie Barthe, who was the daughter of Joseph-Guillaume Barthe.Lavergne studied at the Collège Sacré-Coeur at Arthabaska, the Séminaire de Québec, the University of Ottawa and Université Laval; he later studied in Paris.He articled in law, was called to the bar in 1903 and set up practice at Quebec City and then Montmagny.