Dio states that Artabanus refused because he believed, probably correctly, that Caracalla would use the marriage as an excuse to annex Parthia. Herodian presents a different version, stating that Artabanus was worn down by Caracalla's requests and agreed to the marriage. During a celebration of Caracalla's arrival, probably at the Parthian royal palace in Arbela, Caracalla ordered his troops to massacre the bride and guests.[1] Herodian writes: