In 343 BC, the Macedonian arms were carried across Epirus and a year later Philip II of Macedon turned his military activities towards Thrace. When the Macedonian army approached Chersonese, the Athenians got anxious about the future of their colony. An Athenian general, Diopeithes, ravaged the maritime district of Thrace, an offensive resulting in Philip's rage. The king sent a letter of remonstrance to Athens, demanding the immediate withdrawal of the Athenian troops from Cardia, which was occupied by the Macedonian army. Because of this turbulence, the assembly convened and Demosthenes delivered On the Chersonese, convincing the Athenians, who would not recall Diopeithes.
Content of the speech
Within the same year, Demosthenes delivered the Third Philippic. Putting forth all the power of his eloquence, he demanded resolute action against Philip and called for a burst of energy from the Athenian people. Macedon and Athens were already de facto belligerent parties, since the Athenians were financing Diopeithes, who was launching attacks against allied cities. Most importantly, Philip was the first who violated the terms of the Peace of Philocrates and Athens was just defending its legitimate rights.
The Third Philippic is considered the best of Demosthenes' political orations, because of its passionate and evocative style. From the moment he delivered the Third Philippic, Demosthenes imposed himself as the most influential politician of Athens and the suzerain of the Athenian political arena. He takes the offensive and devitalizes the "pacific" and pro-Macedonian faction of Aeschines. In the Third Philippic, the unchallengeable and passionate leader of the anti-Macedonian faction gives the signal for the Athenian uprising against Philip.