Leto Atreides II (10,207-13,725 A.G.), actually the second son of Paul-Muad'Dib Atreides to bear the name Leto II (the first died at the age of two during the Desert War), known as the God Emperor and the Tyrant, was quite possibly one of the longest-lived humans in history.
Appearances
Dune Messiah
Children of Dune
God Emperor of Dune
Hunters of Dune
Sandworms of Dune