Odaenathus observed all due formalities towards the Emperor, but in practice ruled as an independent monarch. In 266, he launched a second invasion of Persia but had to abandon the campaign and head north to Bithynia to repel the attacks of Germanic raiders besieging the city of Heraclea Pontica. He was assassinated in 267 during or immediately after the Anatolian campaign, together with Herodianus. The identities of the perpetrator or the instigator are unknown and many stories, accusations and speculations exist in ancient sources. He was succeeded by his son Vaballathus under the regency of his widow Zenobia, who used the power established by Odaenathus to forge the Palmyrene Empire in 270.