 The 279 BC invasion of Greece proper was preceded by a series of other military campaigns waged in the southern Balkans and against the kingdom of Macedonia, favoured by the state of confusion ensuing from the complex and divisive succession processes following Alexander's sudden death.The Celtic military pressure toward Greece in the southern Balkans reached its turning point in 281 BC.In 280 BC a great army, comprising about 85,000 warriors, approached from Pannonia and split into three divisions.