The conflict between the French and British was centered around who to control the Ohio Country. Given that Iroquois Confederacy had initially won the region by conquest, they claimed the ownership of the land.
Consequently, the British also claimed that Iroquois confederacy was under them, thus, Iroquois land belongs to them. Similarly, the French laid claim to the ownership of the land. This resulted in conflicts and eventually led to a war, which was known as the French - Indian war between 1754 - 1763. Hence during the war, considering the situation surrounding the land, the Iroquois sided with the British to fought the French.
