The coins are definitely byzantine, on the basis of the garment and sceptre and the XC monogram for Christ.

I'm at a loss for dates unfortunately, but if you want to try your hand at numismatics, here's a list of byzantine emperors some of which show how their coinage looks, and here's a website that deals with Byzantine coins which maybe you can use to attempt to pair up with potential emperors.

If all else fails, it might be possible to email that website with pictures of your coins to see if its something they might be interested in buying, or at least identifying.

I'm no historian, so don't take my word for it, but this is the closest coin I could find. Based on a previous comment saying these coins were byzantine, I looked up some byzantine coins and found one that looks very similar.

http://www.wildwinds.com/coins/byz/michael_VII/sb1880A.jpg

the site I found it on is http://www.wildwinds.com/coins/byz/michael_VII/i.html in the bottom copper coins, most of them look very similar to the one you posted.

Also this one looks very much like yours: http://www.wildwinds.com/coins/byz/michael_VII/sb1878_2.jpg

If this is the same coin, that would make it of Michael VII, just before 1100. I don't want to make any assumptions or make a false claim about this, so I'll just leave it at that.

While you're more than welcome to ask here (and we have a number of Byzantium/ERE experts), you may also want to try /r/whatisthisthing.