The scene is set in ancient Baghdad where the inept and lazy - but thoroughly good-natured - Caliph Haroun el Poussah rules. His second in command is Grand Vizier Iznogoud who has only one aim in life. He wants to eliminate the caliph in order to become caliph himself. However, all stories end in status quo despite Iznogoud's clever schemings.
Although the plots unfold in ancient Baghdad Goscinny had a very anachronistic approach to the events, where more modern inventions and gadgets were often used.

The very title of the series is an easily seen through pun: The grand vizier is no good...