The unfinished one is perhaps that of Arses, who reigned at the longest two years, or, if not his, then that of Darius III.
ARSES, Persian king, youngest son of Artaxerxes III., was raised to the throne in 338 B.C. by Bagoas, who had murdered his father and all his brothers.
In 338 Artaxerxes III., with his older sons, was killed by Bagoas, who raised his youngest son Arses to the throne.
In 338 Bagoas killed the king and all his sons but the youngest, Arses, whom he raised to the throne; two years later he murdered Arses and made Darius III.