When the imperial crown was laid over the cradle of the infant Shapur, the grandees of Persia showered jewels and invoked blessings upon his fledgling reign. To preserve the realm, a wise and auspicious Mobad named Shahru took his seat upon the golden chair of regency, girding his loins in selfless devotion. For five years, Shahru governed the empire with supreme justice and sagacity—distributing wealth to the host, restoring the royal palaces, and guarding the borders against all evil.
As Shapur reached his fifth year, his royal stature began to bloom. One evening in the ancient hall of Ctesiphon, as the golden sun set and the azure veil of twilight enfolded the sky, a thunderous clamor echoed from the direction of the Arvand-rud. Shapur inquired of the wise Mobad the nature of this uproar. Shahru explained that merchants and common folk were hastening from their shops toward their homes, but because the bridge spanning the Tigris was narrow, the crushing throng created bottlenecked terror, sounding like the clash of war-drums.
Upon hearing this, the five-year-old monarch manifested the radiance of Divine Glory. He declared to his counselors that a second bridge must immediately be constructed across the Tigris—one dedicated for going and the other for returning—so that neither merchant nor soldier would suffer distress, funded entirely by the royal treasury. The mobads marveled at the boy-king's precocious benevolence, rejoicing that the tender sapling of royalty had borne such noble fruit.
Seeing her son's brilliant mind, Shapur's mother brought forth the finest tutors in the realm. The young prince mastered all branches of knowledge with astonishing speed. By age seven, he commanded the riding grounds and excelled at polo; by age eight, he bound his waist with war-girdles like the god of war, taking his rightful place upon the exalted throne of his ancestors in the ancient capital of Istakhr.