Original: During the French and Indian War (North American part of the Seven Years' War), the Iroquois sided with the British against the French and their Algonquian allies, both traditional enemies of the Iroquois.
Simplified: During the French and Indian War (the North American part of the Seven Years' War), the Iroquois took the side of the British against the French and their Algonquian allies, both of whom had been enemies of the Iroquois in the past.