Olinthos was for a century, the most important town of Halkidiki. Its foundation is lost in the mythical years. Some archaeological findings show that in the townÉ’s position used to be a significant prehistoric settlement, which was the town of the classical years. According to the mythology Olynthos was the son of Strymonas, King of Thrace and he was killed in a lion hunting. After his death his brother Vraggas build Olynthos in his honor. According to another story Olynthos was the son of Hercules. There are some records for the town which date at the 7th century b.c., when the Vottis conquered it. In 480 b.c. the Persian General Artavazos conquered Olynthos and destroyed the town almost completely. The habitants he arrested were then slaughtered in the swamps, which are located between Olynthos and Potidaia.
After its ruin he gave the town to Halkidis and thus Olynthos became a Halkidian town. After the Persian wars Olynthos became a member of the Athenian Alley. In 440 b.c. he defected form the Athenians and at Perdikas call many coastal towns became neighboring to Olynthos. Thus, Olynthos was so reinforced, according to the historic Xenofon, that could keep a military force of 20,000 men. The foundation of the Common of the Halkidis, that is the political union of 32 towns of Halkidiki under the aegis of Olynthos, it contributed to the further development of the town. During the kingdom of Amyntas B (393-369 b.c.) the dominance of the town expanded to a part of Macedonia, in which Pellas was also included. In 379 b.c. the town was taken by the Lacedaeomonians and broke their Common but very soon Olynthos was set free, reestablished the Common and became so powerful that all the great powers of Greece aimed at its alliance. Philipos of Macedonia in order to detach Olynthos from the influence of the Athenians gave away the fertile land of Anthemounda (current Galatista) and for its sake took over Potidaia. The habitants of Olynthos understood that his behavior was not unselfish so in 352 b.c. broke up the alliance with the Macedonians.
Because the habitants of Olynthos refused to surrender his brother Arridaios, who took refugee to their town, Philippos set out his army against the towns of Halkidis. It is said that the result of this crusade was the disaster of 32 towns of the Common.
Later on he fought Olynthos, which was desperately asking for help from the Athenians. The famous Athenian speaker and politician Dimosthenis announced the Olynthians speeches inviting his town to send help to Olynthos. But when the main Athenian power began, Olynthos took a fall into Philippos hands by betrayal (348 b.c.). The towns fortune had been predetermined by the times of its siege, when Philippos answered to the Olynthian representatives who visited him in order to make peace that either them should be living any more in Olynthos or he in Macedonia. So, after its loot it was completed destroyed. The habitants who were captured were then sold as slaves. Among them were Philippos brothers, Arridaios and Menelaos, who were transferred to Pella and then were killed.