refers to this period. Their peak of development was followed by the gradual decline of the Autariatae ending in 310 BC with their sudden disappearance due to Celtic migrations. As reported by ancient historian Arrian, the Autariatae were one of the three Illyrian tribes that made war against Alexander the Great during his 335 BC campaign. Although modern historians usually assume that the Autariatae and the southern Illyrians were undertaking a joint attack against the Macedonians, it is not explicitly stated by Arrian. Arrian reports that Alexander receaved news of a revolt undertaken by the Illyrian chieftain Cleitus, aided by Glaukias, king of the Taulantii, while the Autariatae were preparing to ambush the main force of Macedon during Alexander's absence. Macedonian ally Langarus, king of the Agrianes, with Alexander's appproval invaded the territory of Autariatae preventing their attack to Macedon. Alexander did not wait the end of Langarus' conflict, but instead quickly moved southward. Langarus took by surprise the Autariatae and plundered their land. After his victory, Langarus returned to his kingdom with rich spoils. According to a modern interpretation, Arrian's account concerning Autariatae's aim to attack Macedonia was likely introduced into writing as a pretext to justify Langaru's raid against Autariatae. The Agrianian king's demand to raid and pillage the Autariatae would have been granted by Alexander because the Macedonian king considered him a trustworthy ally. Arrian mentions in his accounts that the Autariate were a tribe without a king. He also states that Langarus described them as "the least warlike" prople, on the other hand this statement is contradicted by Strabo's accounts, which describe the Autariatae as an expanding tribe of conquerors. Appian (95 – 165) writes that the Ardiaei were destroyed by the Autariatae and that in contrast to the Autariatae had maritime power. He also reports that the Autariatae were punished by Apollo for raiding the Pythian Oracle together with the Celtic Cimbri, after which moment they migrated to the lands of the Getae near the tribe of Bastarnae. This could be an explanation why the Autariatae "disappear" after 310 B.C., according to Wilkes. The ancient geographer, Strabo, lists the Autariatae as one of the three strongest tribes - the other two being the Ardiaei and the Dardanii. The Autariatae and the Celtic Scordisci are thought to have merged into one tribe in the Lower Morava valley, after 313 BC, since excavations show that the two