Largest gold coin of the ancient world - Eucratides I

The largest gold coin of the ancient world is the 20 stater minted by the Greco-Bactrian King Eucratides I (172–145 BC). Weighing 169.2 grams (nearly 5.5 troy ounces) of high-purity gold it is considered a masterpiece of Hellenistic numismatic art. The Greco-Bactrian Kingdom was an independent Hellenistic state (circa 256–120 BCE) that ruled supreme for over a century. It was centered largely in modern day Afghanistan/Uzbekistan. Eucratides I was the last great Greco-Bactrian ruler.

Reverse depicts the Dioscuri (twins Castor and Pollux) on horseback, wielding spears and holding palm branches, surrounded by the Greek legend "ΒΑΣΙΛΕΩΣ ΜΕΓΑΛΟΥ ΕΥΚΡΑΤΙΔΟΥ" (King Eucratides the Great) The large, valuable coin was likely not for circulation, and was probably gifted to those close to the king. Only one authentic example is known to survive. It was discovered in Bukhara, Uzbekistan, in 1867, and was subsequently acquired by Emperor Napoleon III. Today, it is part of the permanent collection at the BnF Cabinet des Médailles in Paris.