Trained by D. Wayne Lukas, Codex was considered the dominant 3-year-old colt in California after winning the 1980 Santa Anita Derby and Hollywood Derby [REF].
Lukas initially declined to nominate Codex for the 1980 Preakness Stakes but the horse was entered accidentally by Lukas' 22-year-old son, Jeff, who worked as the assistant trainer [REF].