Edward Silver Penny Canterbury Mint

Hello!

There are several websites that offer excellent diagnostic aids for the hammered coinage.

In the case of Edward I, the penny issues are classified broadly based on the obverse legend, the style of crown, any adornments on his bust (star, cross, fleur-de-lis, pellet), the style and shape of the letters, face type, and the design of the reverse cross / number of pellets per quadrant. Sometimes there are also useful misspellings, but there are also complications in the form of die muling (mismatched obverse and reverse types.)

Once you have determined a main class, the sorting out is done by the differences in the above.

So if we categorize your coin:

Obverse legend - EDW R ANGL DNS HYB
Bust type - Crowned, "wedge" draped, facing
Bust ornament - None visible
Crown type - Trifoliate, with ornaments, centered fleur-de-lis is tall and wide

Reverse legend - CIVITAS CANTOR (Canterbury mint) with unbarred A's
Cross type - Long with trefoils
Pellets per quadrant - 3

Off the quick diagnostics I would say class 4b but will have to wait until I am at home tonight to properly attribute it.