Loutre's War, he contested the arrival of senior British naval officer John Rous when he arrived at the mouth of the Saint John River to claim it for Britain. He built Fort Boishebert and then later, with the building of Fort Beausejour, Boishébert rebuilt Fort Menagoueche at the mouth of the river, and, disguised as a fisherman, went up and down the coasts of Acadia in order to assess the Acadians' loyalty to France. French and Indian War During the French and Indian War (the North American theatre of the Seven Years' War), in 1754 Boishebert became the commandant of Fort Menagoueche, at the mouth of the Saint John, and there he resisted British efforts to establish themselves. The victory of the British in the Battle of Fort Beauséjour on 16 June 1755 by Monckton's forces marked a turning-point in Boishébert's career. For the remainder of the war, French Officer Boishébert led the Mi'kmaq and the Acadians in a guerrilla war against the British. Immediately after the fort fell, the British commander dispatched a large detachment against the handful of militiamen at Fort Menagoueche. As there was no hope of a successful outcome, Boishébert burned his fort before the enemy arrived and sought refuge among the local populace, continuing meanwhile to fight the enemy. Battle of Petitcodiac Shortly after the Battle of Fort Beauséjour Boishébert learned that the British intended to attack the villages of Chipoudy (Shepody), Petitcodiac (near Hillsborough), and Memramcook; he immediately left for Chipoudy but arrived too late to prevent the village from being destroyed. On 3 Sept. 1755, however, he confronted a British detachment at Petitcodiac. After three hours of desperate struggle, during which they suffered heavy losses (50 killed and 60 wounded), the British fled. Boishébert, who had lost only one man, returned to the Saint John River with 30 of the most destitute families. However, in all, 200 families were able to escape the deportation, and resettle between Shediac and Cocagne. He ordered the Raid on Lunenburg (1756). On January 20, 1756, Boishebert sent Francois Boucher de Niverville to Baie Verte to burn a British schooner. Niverville took the sailors by surprise, killed seven of them, took one prisoner, and burned the ship. At the same time, Boishebert himself led 120 men against Fort Cumberland. On 12 Oct. 1756 he undertook an expedition against Fort Monckton (formerly Fort Gaspareaux, near Port Elgin, N.B.), but