Epigraphic evidence found at Persepolis; alludes to the possibility of a co-regency; saying that Darius ‘left the throne’ 11 years prior to his death. This would lead to a clear, simple succession. However, in another version of the text in Akkadian language, the text says ‘went to his fate’, Dandemaev states that this implies that Darius died, thus ending his rule and creating a more unclear succession to the throne, allowing for other contenders to come forward and state their claim to the throne. Evidence for this power struggle is found in an inscription at Persepolis; ‘Other sons of Darius there were – thus unto Ahuramazda was the desire – Darius my father made me the greatest after himself.’
Xerxes had 2 older half-brothers; both born of Phaedyme, daughter of Gobryas. Both brothers had substantial claims to the throne; according to Ctesias Ariamienes after travelling from Bactria, withdrew his claim to the throne in favour of being offered wealth and the promise of being second in power in the kingdom. In Ctesias’ version of events, Ariamenes crowned the new king; remaing loyal to him and eventually dying, as a hero at Salamas.