On the sailing vessel that was employed to return Bonaventure, Sr., back to France after his defeat at Port Royal, in 1710, one would have seen the man's 9 year old son, Claude-Elizabeth Denys de Bonaventure. The young boy must have been very impressed with his adventurous father and very sad at his death which occurred two years later. Naturally Bonaventure was to follow his father's footsteps and soon found himself being commissioned an ensign at Louisbourg in 1720. He was almost immediately sent to be with his uncle who was in command at Ile Saint-Jean (Prince Edward Island). The French were making efforts to colonize Ile Saint-Jean, but, by 1724 they had given up on their efforts and Bonaventure came back to Louisbourg, a place were he was to spend most all of his military career.
In 1730, Bonaventure made lieutenant; and, in 1737, captain.1 As a young officer he must have worked closely with De Gannes and Duvivier. I do not know whether he was in on the raid of 1744 when Duvivier, having been put in charge, successfully took Canso, or not. I know, he was involved in the attack against Annapolis Royal later that year; he led the sea force, which, arriving in October, was too late to join up with the land forces under De Gannes and Duvivier. The French attacks of 1744 on Canso and Annapolis Royal are dealt with in the context of the larger story on which I work.
In the following year Bonaventure was with the French at Louisbourg when the place was taken by the English colonials in 1745. Like his father in 1710, he too was placed on an English transport and sent back to France on July 4th, 1745 (De Gannes was part of this retiring party; Duvivier, however, was not, as he was already at France having sailed before the 1745 siege began).
Bonaventure, De Gannes and Duvivier were all part of the receiving party when Louisbourg was officially handed back in 1749. Bonaventure was, considering his experience with the place, almost immediately sent to Ile Saint-Jean to build up Port la Joie. In 1754 he was made "king's lieutenant" at Louisbourg, a position which put him second in charge (his poor pay and his poor health continued). Thus, we see that Bonaventure was to have a principal role during the second siege of Louisbourg in 1758. For the second time he was loaded on an English transport and return to Rochefort where he continued on with his military duties; he died there in 1760, likely just before the news was received that all of New France had fallen, permanently, into English hands.
 McLennan, in his Louisbourg, sets out a very short note on Bonaventure's military advancement, beginning with his appointment as as an Enseigne in 1720. (Appendix I, p. 332).