Byname SHAPUR THE GREAT, 10th king of the Sasanian Empire of Persia, who withstood Roman strength by astute military strategy and diplomacy and brought the empire to the zenith of its power.
Early life and accession.
The name Shapur, meaning "son of a king," was common in the Sasanian period and was often given to sons other than princes. Numerical designations were not used to distinguish kings of the same name; instead, the family genealogy was cited. Thus, in one inscription, Shapur styles himself, the Mazdah-worshipping god Shapur, king of kings of Iran and non-Iran, who is a scion of the Gods, the son of Hormizd (Ormizd II), the grandson of Narses.
According to tradition, his father died before Shapur was born, and the child was proclaimed king by the Persian nobility at his birth in 309, in preference to his brothers. After a regency, he apparently took the realm into his own hands in 325 at the age of 16.