Iznogoud is the second in command (Grand Vizier) to the Caliph of Baghdad Haroun El Poussah (Haroun El Plassid in English, a pun on the historical Caliph, Harun al-Rashid) but his sole aim in life is to overthrow the Caliph and take his place. This is frequently expressed in his famous catchphrase, "I want to be Caliph instead of the Caliph" ("je veux devenir calife à la place du calife"), which has passed into everyday French for qualifying over-ambitious people who want to become chief. Iznogoud is always assisted in his plans by his faithful henchman, Dilat Larath (Wa'at Alahf in English).
A typical example is when the Grand Vizier discovers the "Road to Nowhere", a road that only leads back to itself, and devises a plot to lure the Caliph there so he will become eternally trapped. In his excitement over the prospect to accomplish his life's mission, Iznogoud forgets that he needs an exit for himself. Another plan involves freezing the Caliph, which has to be shelved because there always seems to be some source of heat nearby. Iznogoud also attempts to enlist the services of a primitive computer (described as a very clever djinni) in order to find out the answer to his perennial ambition. The temperamental computer ends up sulking when Wa'at Alahf answers a complex mathematical equation before it can. In the end, the only answer Iznogoud gets is the solution to the equation. As in every Iznogoud story, Iznogoud is ultimately unsuccessful, and the Caliph continues his reign.
In more recent English translations Haroun El Plassid has the title of Sultan rather than Caliph to avoid offending the Muslim community.