Scholarly dating methods disagree sharply: oral-tradition king-list counting, astronomical (solar eclipse) dating, and archaeological evidence for the confederacy's founding place estimates anywhere from roughly 1142 AD to 1451 AD, a span of three centuries, with no consensus resolution (Wikipedia, wikipedia-great-peacemaker).
What would resolve this A convergence of independent dating methods (archaeological, astronomical and documentary) on a single narrower window, or a documented primary source fixing the founding date.
OpenHistorical chronology, archaeology, oral tradition studiesWikipedia: Great Peacemaker