Back to Byzantium (but really Ravenna, Italy).  Here is a solidus of Heraclius and his son Heraclius Constantine as depicted on a superb coin of the Ravenna mint.  This particular coin was produced during the reignal year of 613/614 as indicated by the B at the end of the legend.  Unlike coinage from Constantinople, Ravenna did not have multiple officinaes (submints) producing gold coinage.  Therefore, they marked there coins with a indicator (indictional) of the reignal year.  This is why this coin can be precisely dated to a one year period of time.  This coin has polished dies on both sides, higher than normal relief and weighs 4.51 grams.

During the period of Justin II (565) through the early part of the reign of Constantine IV (~670), the Ravenna mint replaced the Rome mint as the producer of the finest quality coinage of the empire.  There are many possible reasons for this superior quality coinage, but the most accepted one is that the Ravenna mint did not have the heavy demands of producing large quantities of coinage, as the Constantinople mint did.  Therefore, a considerable larger amount of time and care went into both the production of the dies and the coins themselves.  While this particular coin is exceptional, most of the coinage from Ravenna during this period of time exhibit a style that much more attractive than the Constantinople counterpart.  Unfortunitely, the coinage of Ravenna, during this period of time, is quite scare and usually demands at least a 100% premium to that of Constantinople, if not more.