With the cession in 1713 of Acadia to the British the Duviviers were sent to the new colony of Île Royale (present-day Cape Breton Island) where, through various business endeavours they became one of the wealthiest and most prestigious families.
François upheld his family's strong military traditions, enlisting as a cadet in the French troupes de la marine in 1716, and being commissioned an ensign three years later.
Through a series of trading ventures with New England, the West Indies, and France, canny manipulation of the law, and the usage of his military rank as leverage he earned a reputation as a businessman of great acumen who was not afraid to use unscrupulous business practices to further his own ambitions.
In 1747, he resigned his captain's commission only to rejoin at half pay in 1749 in order to make a bid for the governorship of Île Royale, newly restored to the French in the Treaty of Aix-la-Chapelle.
Records of Duvivier disappear for the next twenty years, but it can be presumed that he spent most of this time living on his estate at Le Vivier, near Chalais in the commune of Sérignac before dying on 28 May 1776.