The Longhouse Religion, Gaiwiio or the Good Message, is the traditional religion of the Haudenosaunee Confederacy, and its medicine societies hold ceremonial knowledge, including the False Face healing masks, that this article does not reproduce or describe in appearance. Its public history is well documented. In the early nineteenth century, after decades of upheaval scholars including Daniel K. Richter have traced through the colonial era, the Seneca prophet Handsome Lake reformed Haudenosaunee religious practice around a code of moral teaching that spread through the Six Nations and remains the basis of Longhouse worship today. The religion's ceremonial year, from the Midwinter Ceremony through Maple, Planting and Green Corn to the Harvest Ceremony, gives thanks to the Creator through set forms of speech, song and dance held at the longhouse of each Haudenosaunee nation.
The False Face masks are a separate matter of public record: the Confederacy, through the Central Fire at Onondaga, has formally asked that they not be reproduced, displayed or sold, and major museums have withdrawn images of them from public view on that basis. That is a request the outside world can be seen honoring, and this article honors it too, recording that the masks exist and what kind of institution holds them without showing one.