The Monarchs of England have been memorialized in many different artistic medals. This example is of King Edward II, who reigned between 1307 and 1327. There is a terrific web site that summarizes these medals, and more, at Historical and Commemorative Medals [Press Here], the collection of Benjamin Weiss. For the English kings and queens, their birth, coronation, and death dates usually appear on the medal. The medals themselves have been produced since the 1700s.
To evaluate a specific medal, you must detect its composition and its date of manufacture. Most medals are made of bronze, but some are made of red or brown porcelain. It is easy to determine composition, but date of manufacture is a different story. Usually it takes an experienced numismatist (coin collector) to discern whether or not a bronze medal was struck in recent times, after, say, 1940. Many medals have been produced as re-strikes, that is, they use the original or look-alike dies, but the medal itself is only a few years old. The porcelain medals are all old.
Here are very approximate catalog values: