The Palmyrene monarchy was new; allegiance was based on loyalty to Odaenathus, making the transfer of power to a successor more difficult than it would have been in an established monarchy. Odaenathus tried to ensure the dynasty's future by crowning his eldest son co-king, but both were assassinated. Zenobia, left to secure the Palmyrene succession and retain the loyalty of its subjects, emphasized the continuity between her late husband and his successor (her son). Vaballathus (with Zenobia orchestrating the process) assumed his father's royal titles immediately, and his earliest known inscription records him as King of Kings.