The Revenge Tragedy was a popular genre of drama during the Elizabethan and Jacobean eras. Thomas Kyd's The Spanish Tragedy is one of the earliest examples of this type of play. Likewise, William Shakespeare's Hamlet has often been considered a revenge tragedy. According to William Harmon and C. Hugh Holman in their book A Handbook to Literature, revenge tragedies generally include the revenge of a father for his son, or vice versa, often directed by a ghost. Other characteristics may include insanity, suicide, intrigue, sensational horror, and a scheming villain.