Over a decade after Herbert's death, his son Brian Herbert enlisted science fiction author Kevin J. Anderson to coauthor a trilogy of "Dune" prequel novels that would come to be called the "Prelude to Dune" series. Using some of Frank Herbert's own notes, the duo wrote ' (1999), ' (2000), and ' (2001). The series is set in the years immediately prior to the events of "Dune". This was followed with a second prequel trilogy called the "Legends of Dune", consisting of ' (2002), ' (2003), and ' (2004). These were set during the Butlerian Jihad, an element of backstory which Frank Herbert had previously established as occurring 10,000 years before the events chronicled in "Dune". Herbert's brief description of humanity's "crusade against computers, thinking machines, and conscious robots" was expanded by Brian Herbert and Anderson in this series.