A tutelary spirit or patron god is a god, often a minor god, who serves as the guardian or watcher over a particular site, person, or nation. For example, in Greek polytheism, Athena was the patron goddess (or "matron goddess") of the city of Athens; in Roman polytheism, Janus was the patron god of doors, gates, and the like. Belief in tutelary gods or spirits often reflects a tradition of animism.