Hi, Please Help Identify Roman(?) Coin

Hello yuval! This coin is not Roman, in fact it is of the Byzantine Empire! I am much less familiar with the coinage of the Byzantines, but there are several key factors that show me that it is theirs.

1) The size of this coin is a whopping 30mm, a HUGE coin for its time period (and the present!). Late Roman bronze coins were much smaller than this.

2) The obverse portrait, or whats left of it, is very crude in appearance. This is due to the lesser quality dies and much less care the Byzantines used and put into the minting of their coins. Roman coins have very sharp and detailed images.

3) The reverse depicts a huge 'M', which is very typical of the Byzantine Empire.

Now I am afraid that is where my knowledge of this coin ends...someone else will have to help you attribute it. I must warn you though, it is in pretty rough shape so it may be impossible to attribute it fully. Perhaps it is Anastasius I....?

Edit: I noticed a few faint letters under the 'M' on the reverse after my initial posting. I see CON, so this was minted in Constantinople.