bah. I think I decoded this as Heraclius with Heraclius Constantine AE follis 610AD......:
Obverse: Heraclius to left, Heraclius Constantine to right, standing, facing, cross in upper field. Heraclius crowned and in military dress, holding long cross. Heraclius Constantine with short beard, crowned, wearing chlamys and holding globus cruciger. Some kind of monogram to low left of Heraclius
Reverse: Large M between A/N/N/O and regnal year. C above (cross should be further above), (Delta) in middle of M, CON in exergue
rather scarce, nice patina
31mm, 11.49 grams
Sear Byzantine 810