Owner Comments:
This type is thought to have been issued in celebration of the Ptolemaic victory over the Seleukids at the battle of Raphia during the Fourth Syrian War. Official propaganda proclaimed that these two deities, Serapis and Isis, had intervened on behalf of the Egyptians, saving them from defeat (see C. Lorber, “The Ptolemaic Era Coinage Revisited,” NC 2007, p. 116, and L. Bricault, “Serapis et Isis, Sauveurs de Ptolémé IV à Raphia,” Chronique d’Égypte LXXIV (1999), pp. 334-43).
You will note that the eagle on the thunderbolt appears in essentially the same form on the gold Roman coins that would be struck just a few years after this coin. Some people think Rome got gold support from Ptolemy and this reverse on the Roman coins was a tribute to the gold donor. We know from his own huge gold coins that Ptolemy IV had a lot of gold.
Thomas Landvatter, in his die study cited above that appeared in the 2012 ANS American Journal of Numismatics (Second Series, Vol. 24, p. 88), suggests that this issue was “carrying a very specific ideological message directed more widely throughout the empire: Ptolemy IV was equating himself and his wife Arsinoe with the divine sibling-spouses Serapis and Isis.” Landvatter also notes that “[t]his was an ideological statement made during wartime, meant to have wide appeal and explicitly associate the Ptolemaic king and queen with two of the most popular deities in the Eastern Mediterranean.” Indeed, the popularity of the Serapis/Isis cult would outlive the Ptolemaic dynasty and continue well into the Roman Imperial period, only to be eventually usurped by the Christian and Muslim faiths.