<P> Sparta and its allies , with the exception of Corinth , were almost exclusively land based powers , able to summon large land armies that were very nearly unbeatable . Under the direction of Pericles , the Athenians pursued a policy of retreat within the city walls of Athens , relying on Athenian maritime supremacy for supply while the superior Athenian navy harassed Spartan troop movements . Unfortunately the strategy also resulted in adding many people from the countryside to an already well - populated city , introducing a severe crowding factor as well as resource shortages . Due to the close quarters and poor hygiene exhibited at that time Athens became a breeding ground for disease and many citizens died including Pericles , his wife , and his sons Paralus and Xanthippus . In the history of epidemics the ' Plague ' of Athens is remarkable for its one - sided affliction and bias on the ultimate outcome of a war . </P>
why was the plague that struck athens so devastating
close quarters and poor hygiene