The nobles objected to him, not only for the murder of his father, but his descent from an Italian concubine, and the incestuous commerce which he was supposed to maintain with her.

They had perhaps grounds for this last charge.

At any rate Phraataces provoked suspicion by the singular favors and honors which he granted to a woman whose origin was mean and extraction foreign.

Not content with private marks of esteem and love, he departed from the practice of all former Parthian sovereigns in placing her effigy upon his coins; and he accompanied this act with fulsome and absurd titles.

Musa was styled, not merely "Queen," but "Heavenly Goddess," as if the realities of slave origin and concubinage could be covered by the fiction of an apotheosis.
It is not surprising that the proud Parthian nobles were offended by these proceedings, and determined to rid themselves of a monarch whom they at once hated and despised.