Why does the author start the novel with the prophecy quote on p. 1?

Chapter One begins with a poetic transcription of the true-life prophecy delivered to Chief Powhatan by his religious authorities before the first colonists arrived in 1607. It predicts the coming of a group of people from Chesapeake Bay who will move onto Powhatan's tribal lands. It prophesied three battles, the first two of which would end in victory for Chief Powhatan, but that the last would destroy his empire.

The reader finds that each chapter begins with a real-life quotation from a text contemporary to the historical time of the novel, each foreshadowing the action that is to come. Chapter One's prophecy foreshadows the entire novel: Chief Powhatan and his people are a powerful empire, and a religious prophecy has predicted the coming of the English settlers, who will suffer through two defeats before subduing the Indians. The reader can expect the prophecy to come true, because the general defeat of the Native Americans by the colonists is a well-known story.