Edward Cornplanter or So-son-do-wa (1856–1918) was a chief of the Seneca people of the Iroquois Nation (Haudenosaunee) and a leading exponent of the Code of Handsome Lake (Gai'wiio, also known as the Longhouse Religion). Cornplanter, the son of Moses and Sarah (Phillips) Cornplanter, was born in November 1856 on the Seneca Cattaraugus Reservation. He was the great-great-grandson of Chief Cornplanter, who led the tribe during the American Revolutionary War. His Seneca name So-son-do-wa means "Deep Night." Cornplanter died on June 10, 1918, at the Cattaraugus Reservation.