Aeneas Tacticus (4th century BC) was one of the earliest Greek writers on the art of war and is credited as the first author to provide a complete guide to securing military communications. 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: ), 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.