[1][2] Joncaire successfully negotiated a peace between New France, the Onondaga, Seneca, and other Iroquois tribes (except for the Mohawks).
[1] In early 1720, Vaudreuil assigned Joncaire the task of acquiring permission from the Seneca to construct a French post to defend against a planned English occupation of the area around Niagara Falls.
[1] Joncaire convened a meeting of Seneca chiefs and informed them of his desire to have his own house so that he could visit them more frequently.
[6] Joncaire gained permission from the Iroquois to expand Fort Niagara from a trading house to a wooden stockade capable of holding 300 men.
[1][2] In 1753, Governor Jean de Lauson sought to build a fortified trading post at the confluence of the Allegheny River and French Creek at Venango.
[7] That year, the English traders were expelled from Venango and Philippe-Thomas Chabert de Joncaire established Fort d'Anjou at the location.
[8] After leaving for France, he was implicated in the Canada Affair and imprisoned in the Bastille, before returning to America and then dying in Detroit in 1771.