The Selinuntines are next mentioned in 466 BCE, co-operating with the other cities of Sicily to help the Syracusans to expel Thrasybulus. Thucydides speaks of Selinunte just before the Athenian expedition in 416 BCE as a powerful and wealthy city, possessing great resources for war both by land and sea, and having large stores of wealth accumulated in its temples. Diodorus also represents it at the time of the Carthaginian invasion, as having enjoyed a long period of tranquility, and possessing a numerous population. The walls of Selinunte enclosed an area of approximately . The population of the city has been estimated at 14,000 to 19,000 people during the fifth century BC.