In the eighth book of Statius' Thebaid the Argives meet to appoint a successor to the dead seer Amphiaraus (275 ff.). Their choice falls on Thiodamas son of Melampus (277–9); he, however, is overwhelmed by the prospect, which he regards with a mixture of joy and apprehension (281–5). There follows an eight-line simile which David Vessey rightly describes as ‘unique in the Thebaid’ Thiodamas is compared to a young Parthian king who succeeds to the throne following his father's death (286–93):
sicut Achaemenius solium gentisque paternas
excepit si forte puer, cui vivere patrem
tutius, incerta formidine gaudia librat,
an fidi proceres, ne pugnet vulgus habenis,
cui latus Euphratae, cui Caspia limina mandet.
sumere tune arcus ipsumque onerare veretur
patris equum, visusque sibi nee sceptra capaci
sustentare manu nee adhuc implere tiaram.