Solidus - Heraclius and Heraclius Constantine Constantinopolis

Heraclius introduced the co-emperorship of his son Heraclius Constantine almost immediately after the boy's birth in 612, a dynastic hedge against the existential threat posed by the Sasanian Persian advance that would, within a decade, temporarily strip Byzantium of Egypt, Syria, and Palestine. The solidus maintained its gold standard through the crisis, functioning as the instrument by which Heraclius paid his armies and negotiated alliances — including the pivotal Khazar alliance of the 620s that helped turn the war's tide.

BCV#738 covers a long span, and dies from the earlier years of this type show notably cruder workmanship than later issues, a direct consequence of workshop disruption during the Persian occupation of the eastern mints.