Darius was followed by his son Xerxes, Xerxes was followed by his son Artaxerxes, Artaxerxes was followed by his son Darius II, not another Artaxerxes.
UDarius walandelwa yindodana yakhe uXerxes, uXerxes walandelwa yindodana yakhe u-Aritahishashita, u-Aritahishashita walandelwa yindodana yakhe uDarius II, hhayi omunye u-Aritahishashita.