Onontio was a title used by North American Indians of the Great Lakes region to refer to the governor of New France.
Onontio is a Mohawk rendering of "great mountain", the folk etymology translation of "Montmagny".
Onontio fell from power in 1763 with the conquest of New France by the British empire in the Seven Years' War.
As a result, the natives of the Great Lakes rose up against British rule in Pontiac's Rebellion, attempting in part to restore Onontio to power.
The native war effort was a failure militarily, but the British revised their policies and began to fulfill some of Onontio's duties.