This coin is a tetrachalkon from Rhodes struck between 229 and 205 BCE. It's a pretty special coin - and I'll try to explain why :)
Coins from Rhodes typically feature a rose on the reverse (back) - this is a play on words because the Greek work for rose is Rhodon - and Helios the sun god on the obverse (front). In fact, Helios was so important to Rhodes that they built a huge statue honouring him - the Colossus of Rhodes - on the entrance to the Harbour. It was 33 meters tall, roughly the same size as the Statue of Liberty today, and is recognized as one of the original wonders of the ancient world.
This particular issue features Zeus, though. Why? Well, around 226 BCE Rhodes was struck by a devastating earthquake which toppled the statue and destroyed much of the city and harbour. This was a significant event, and Greek states from all over the Mediterranean sent help and offers to help rebuild the city and raise the statue again.
According to Strabo, the statue had broken off at the knees. An oracle was consulted, and told the citizens of Rhodes not to rebuild it, and so they turned down this part of the relief effort.
The most important and riches of Greek kings at this time was Ptolemaios III of Egypt. In fact he was so generous that the Rhodeians must have wanted to honour him in some way.
And so they struck this coin - you see, Egyptian coins at this time almost always featured Zeus on the obverse in a very recognizable style which is replicated here. It is difficult to explain the obverse motif without this Egyptian connection, at least.
I bought this coin some 6 years ago, and I don't see many of them around. It wasn't particularly expensive, but it has a special place in my collection because I find the circumstances for it being struck so fascinating.
Obverse: Laureate head of Zeus right
Reverse: P - O, Rose with bud to right. Control: TE to left
18mm, 5.73g
Ashton 234; HGC 6, 1469.
