Complex sentence: The Iroquois named "Sayenqueraghta" and Cornplanter as war chiefs of the four nations that allied with the British: the Mohawk, Seneca, Onondaga and Cayuga.
Split into simpler sentences: The Iroquois named Sayenqueraghta and Cornplanter as war chiefs of the Iroquois. Four of the Iroquois nations were allies of the British: the Mohawk, Seneca, Onondaga and Cayuga.