AE1

If the wording on your coin is readable, even if only a few letters, enter them into the search field of the database and see what comes up. Having readable letters on your coin is the best-case scenario as it should be fairly easy to at least narrow down the possible emperors under whose reign the coin was minted. If you get too many "hits" try guessing the letters to the right or left of the readable part so as to make a longer letter sequence. Repeat the search for the other side of the coin if any of the letters there are readable. Running this secondary search will likely return different emperors. However, only the emperors that match BOTH sequences will be the good candidates. Use the many other clues the coin provides to make a match. For coins made up to about the year 300 the portraits are unique to each emperor so this should be cross-referenced against the typical portraits of those emperors.