Philip had made a preliminary visit to…
357 BCE
Philip had made a preliminary visit to the strategically and politically crucial area of Thessaly in 358 BCE, and is now poised for a “blitzkrieg” against Amphipolis in Thrace, the strategic key securing Macedon's eastern frontier and giving access into Thrace.
Amphipolis had broken away from its mother city, Athens, in 442 at the end of the first decade of the Peloponnesian War, maintaining its independence ever since.
At the time of his assault on Amphipolis, Philip keeps the Athenians quiet by promises that he will hand it over to them.
After besieging and capturing the city in 357, he instead incorporates Amphipolis into Macedon and distributes its territory to Macedonian feoffees.