Plague during wartime, aka Strategy and Context

Unexpected things happen to even great strategists.

Year 1 of the war against Sparta over, great oration given, year 2? Pericles died of the plague.

Here is Thucydides:

Such was the funeral that took place during this winter, with which the first year of the war came to an end. [2] In the first days of summer the Lacedaemonians and their allies, with two-thirds of their forces as before, invaded Attica, under the command of Archidamus, son of Zeuxidamus, king of Lacedaemon, and sat down and laid waste the country. [3]Not many days after their arrival in Attica the plague first began to show itself among the Athenians. It was said that it had broken out in many places previously in the neighborhood of Lemnos and elsewhere; but a pestilence of such extent and mortality was nowhere remembered. [4]Neither were the physicians at first of any service, ignorant as they were of the proper way to treat it, but they died themselves the most thickly, as they visited the sick most often; nor did any human art succeed any better.Supplications in the temples, divinations, and so forth were found equally futile, till the overwhelming nature of the disaster at last put a stop to them altogether.

– Thucydides. The Peloponnesian War. London, J. M. Dent; New York, E. P. Dutton. 1910.
Pericles starts the Peloppenisian War 430, dies 429 and Athens loses 404 bce, Athenian democracy restored 403 bce.
Socrates killed 399 bce at age 60ish.
September 11, 490 bce: The Battle of Marathon repelling Darius, then repulsion of Xerxes 15 years later by Themistocles and Spartan coordination. Shortly thereafter, rise of Pericles and war between Sparta and Athens for 50 years.