I also have little knowledge of coin of the Byzantine empire, but this does seem to remind me of a coin of John II or a later Byzantine emperor , but the image of two people is common on Byzantine coins and it could be any emperor for all i know. Unfortunately due to the lack of defined detail and only having a one side with visible detail, i am not able to help you any further, but will keep a look out for some more accurate information. Hopefully someone more educated in the coinage of the Byzantine empire will be able to help you.