Expansion of Macedonia under Philip II
The Third Sacred War (often just called 'the' Sacred War) broke out in 356 BC, and would present Philip with his first real opportunity to expand his influence into the affairs of central and southern Greece. The war was ostensibly caused by the refusal of the Phocian Confederation to pay a fine imposed on them in 357 BC by the Amphictyonic League, a pan-Greek religious organisation which governed the most sacred site in Ancient Greece, the Temple of Apollo at Delphi. Behind the religious element, there probably lay a display of "realpolitik" in bringing charges against the Phocians, instigated by the Thebans. At this time, Thebes controlled a majority of the votes in the council, and at the autumn meeting in 357 BC, the Thebans were able to have both the Phocians (for the cultivation of the sacred land) and the Spartans (for occupying Thebes some 25 years previously) denounced and fined. Since the fines for both parties were "unjustifiably harsh", the Thebans probably expected neither party to pay, and thus to be able to declare a "sacred war" on either.
History of the Cyclades
According to Demosthenes and Diodorus of Siculus, the Thessalian tyrant Alexander of Pherae led pirate expeditions in the Cyclades around 362-360 BC. His ships appear to have taken over several ships from the islands, among them Tinos, and brought back a large number of slaves. The Cyclades revolted during the Third Sacred War (357-355 BC), which saw the intervention of Philip II of Macedon against Phocis, allied with Pherae. Thus they began to pass into the orbit of Macedonia.