Aristotle is thirty-nine in 343 BCE when…

Bagoas rules the court and the upper satrapies after the king's return to Susa, working in close partnership with Mentor of Rhodes, who restores the authority of the empire throughout the west.

Artaxerxes II of Persia has subdued Phoenicia and Cyprus, and advances now on Egypt with a great land and naval force.

The Great King is said to have devastated parts of Palestine in 343 in connection with his reconquest of Egypt.

Artaxerxes defeats the pharaoh Nectanebo II at Pelusium in the Nile River delta in 343.

A Persian satrap is placed over Egypt and its puppet Thirty-First dynasty, the walls of its cities are destroyed, its temples are plundered, and Artaxerxes reportedly kills the Apis bull with his own hand. (The local dynasty flees south to Nubia, where it will maintain an independent kingdom that will keep alive the hopes of a national revival.)

Bagoas, commander in chief of the Achaemenid forces, gains wealth by selling back to the priests at an exorbitant price the sacred writings looted from Egyptian temples.

Phocion helps the Megarians defend themselves against Philip in 343 BCE.

The issue with Aeschines comes to a public trial, in which Demosthenes and Timarchus seek to prosecute Aeschines for treason.

Demosthenes, in his speech The False Legation, accuses Aeschines of rendering false reports, giving bad counsel, disobeying instructions, and being susceptible to bribery.

In retaliation, Aeschines successfully indicts Timarchus for gross immorality, and at his own trial in the autumn of 343, a narrow majority acquits him, Aeschines having defended himself against the charge in his speech On the False Embassy.

Philip II of Macedon quite easily assimilates the Odrysian kingdom in Thrace, which had in about 360 split into three polities.

According to legend, when Philip attacks the Getae, they send out against him priests robed in white and playing lyres.

He makes another and final move against Thrace in 342, removing the first local recalcitrant, Cersobleptes.

From the economic as well as the political point of view, subduing the Thracian rulers has been well worth the effort: …

…the gorgeous Thracian Treasure from Rogozen in Bulgaria, discovered in 1986, consists of one hundred and sixty-five high-grade silver and gilded vessels; one of them is inscribed “Property of Cersobleptes.”

Philip captures the Thracian settlement of Eumolpias, situated on approximately four hundred-feet-high (one hundred and twenty-meters) cliffs above the Maritsa River, in 342 and renames the city Philippopolis (present Plovdiv, in south central Bulgaria, about eighty-five miles (one hundred and forty kilometers) southeast of Sofia).

Aristotle, a graduate of the Academy's program to train young men for a political career and to provide advice to rulers, had joined the court of Hermias of Atarneus, tyrant of Assus in Ionia, following Plato's death in 347 BCE.

Xenocrates, a friend and classmate of Aristotle's, has accompanied Aristotle to Asia Minor, where Aristotle has established a Platonic school, but the Persians capture and kill Hermias in 342 BCE, necessitating his return to Greece.

Philip begins the series of campaigns in Thrace in 342 BCE that will enable him to annex great parts of it as a province within two years , and finally to demonstrate his power against the Scythians settled on the southern banks of the Danube Delta.