Aeneas Tacticus in Wikipedia
Aeneas Tacticus (4th century BC) was one of the earliest Greek writers on the art of war.
According to Aelianus Tacticus and Polybius, he wrote a number of treatises (Hypomnemata) on the subject. The only extant one, How to Survive under Siege (Greek: Περὶ τοῦ πῶς χρὴ πολιορκουμένους ἀντέχειν), deals with the best methods of defending a fortified city. An epitome of the whole was made by Cineas, minister of Pyrrhus, king of Epirus. The work is chiefly valuable as containing a large number of historical illustrations.
Aeneas was considered by Casaubon to have been a contemporary of Xenophon and identical with the Arcadian general Aeneas of Stymphalus, whom Xenophon (Hellenica, vii.3) mentions as fighting at the Battle of Mantinea (362 BC).