After the people who spoke Iroquoian came together as different tribes , which were mostly in what is now central and upstate New York , in the 16th century or earlier they came together in an group known today as the Iroquois League , or the `` League of Peace and Power '' . After the Iroquoian-speaking peoples coalesced as distinct tribes , based mostly in present-day central and upstate New York , in the 16th century or earlier they came together in an association known today as the Iroquois League , or the `` League of Peace and Power '' .