Duniverse and the Legacy

Written by Frank Herbert himself before his passing in 1986, there are 6 original books. His original epic chronology consists of 1 – Dune (1965), 2 – Dune Messiah (1969), 3 – Children of Dune (1976), 4 – God Emperor of Dune (1981), 5 – Heretics of Dune (1984), 6 – Chapterhouse: Dune (1985).
Decades later, his son Brian Herbert, alongside co-author Kevin J. Anderson, took Frank’s leftover physical notes and expanded the “legacy” universe with dozens of prequels and sequels. However, hardcore fans separate the two, Frank’s original six books are considered the true, untouchable canon.