Divination forms an unexpectedly high proportion of our total information on Sparta’s politics, internal and external. It should be studied diachronically, as well as generically. To abstract it from secular and political context would conceal both causes and effects of religious credulity. We read that Sparta’s hereditary dyarchs, the state’s chief generals, were appointed, controlled and deposed according to the interpretation of omens and oracles. Grand omens in particular were respected, such as earthquake or a succession of military failures. This (...) was in keeping with the Spartan bias in favour of events that all could perceive. Sparta’s kings made famous and apparently extravagant claims to have privileged ancient links with the gods. But by studying the political vulnerability of the kingship, we see these religious pretentions as defensive, the most effective shield for an institution under threat. (shrink)