Paeonia, the land of the Paeonians, originally including the whole Axius (Vardar) River valley and the surrounding areas, in what is now northern Greece, Macedonia, and western Bulgaria. The Paeonians, who were probably of mixed Thraco-Illyrian origin, were weakened by the Persian invasion (490 bc), and those tribes living along the Strymon River (in western Bulgaria) fell under Thracian control. The growth of Macedonia forced the remaining Paeonians northward, and in 358 bc they were defeated by Philip II of Macedonia. The native dynasty, however, continued to be highly respected: about 289 bc, King Audoleon received Athenian citizenship, and his daughter married Pyrrhus, king of Epirus. Under the Romans, Paeonia was included in the second and third districts of the province of Macedonia. By ad 400, however, the Paeonians had lost their identity, and Paeonia was merely a geographic term.