Heraclius and Heraclius Constantine. 610-641 AD. AV Solidus, Constantinople. 

dd NN hERACLIUS ET hERA CONST PP, facing busts of Heraclius, with moustache, short beard and tufts of hair at ears, on left, and Heraclius Constantine, (<b>bust almost same size</b>), beardless on right, both wearing chlamys and <u>simple</u> crown with cross on circlet; cross between their heads.
VICTORIA AVGU and officina letter I, cross potent on three steps, I in right field.

Mintmark CONOB. 

SB 744; DOC 21b; MIB 23; Tolstoy 159 (this coin).

Image copied from Tolstoy.