ssion of the Hellespont and Bosphorus, and the
Greek cities on their coast, of the greatest value to Athens, since she
relied upon the possession of the straits for the unobstructed importation
of corn. The Athenians now began to realize the encroaching ambition of
Philip, and to listen to Demosthenes, who, about this time, B.C. 341,
delivered his third Philippic. From this time to the battle of Chaeronea,
the influence of Demosthenes was greater than that of any other man in
Athens, which too late listened to his warning voice. Through his
influence, Euboea was detached from Philip, and also Byzantium, and they
were brought into alliance with Athens. Philip was so much chagrined that
he laid siege to Perinthus, and marched through the Chersonese, which was
part of the Athenian territory, upon which Athens declared war. Philip, on
his side, issued a manifesto declaring his wrongs, as is usual with
conquerors, and announced his intention of revenge. The Athenians fitted
out a fleet and sent it under Chares to the Hellespont. Philip prosecuted,
on his part, the siege of Perinthus, on the Propontis, with an army of
thirty thousand men, with a great number of military engines. One of his
movable towers was one hundred and twenty feet high, so that he was able
to drive away the defenders of the walls by missiles. He succeeded in
driving the citizens of this strong town into the city, and it would have
shared the fate of Olynthus, had it not been relieved by the Byzantine and
Grecian mercenaries. Philip was baffled, after a siege of three months,
and turned his forces against Byzantium, but this town was also relieved
by the Athenians, and the inhabitants from the islands of the AEgean. These
operations lasted six mouths, and were the greatest adverses which Philip
had as yet met with. A vote of thanks was decreed by the Athenians to
Demosthenes, who had stimulated these enterprises. Philip was obliged to
withdraw from Byzantium, and retreated to attack the Scythians. An
important reform in the administration of the marine was effected by
Demosthenes, although opposed by the rich citizens and by AEschines.

(M718) While these events transpired, a new sacred war was declared by the
Amphictyonic Council against the Locrians of Amphissa, kindled by
AEschines, which more than compensated Philip for his repulse at Byzantium,
bringing advantage to him and ruin to Grecian liberty. But the Athenians
stood aloof from this suicidal war,