Hetairenreiterei
Philip then went on campaign against the Illyrians, particularly Pleuratus, whose Taulantii kingdom probably lay along the Drin river in modern Albania and was the main independent power in Illyria after Grabus' defeat. During the campaign, Philip suffered a smashed shin-bone, and was only saved from death by the bravery of his Companion cavalry (150 of whom were wounded in the process). Philip did not campaign in 344 or 343 BC, which may have been due to the effects of this severe injury. Instead, Philip contented himself with reorganising Thessaly in 344 BC, reinstating the ancient fourfold "Tetrarchic" administration system.