Today's saint was a good opportunity to learn something new. I had vaguely heard of the pagan god Dagon, but had not heard of Marnas at all. Like many of the polytheistic gods, these got vaguely conflated as the cultures spread and blended. He was variously a fish god, a grain god, and a protector / warrior god. He was also variously identified with Cronus, Enlil, Zeus (especially the Cretan Zeus), and Marnas. And that last identity brings us to St. Porphyrios.
A monk from Thessalonica, Porphyrios made a pilgrimage to the Holy Land but was stricken with a liver disease while there. Being a holy man in a holy land, he holed up in a cave in Jordan for five years. He must have recovered somewhat because he moved to Jerusalem, where he was appointed Keeper of the Cross. Three years later, he became bishop of Gaza, and here's where his story intersects with Marnas/Dagon.
The monotheists had been battling against the adherents to Dagon since the reign of King Saul. Even though Christianity had become the lawful religion throughout the whole Roman Empire, the Temple of Marnas (the Marneion) in Gaza was the last great pagan cult center. I tend to think that Porphyrios' fame rests largely on his ability to muster the imperial will to destroy this building, right down to removing the sacred floorstones on which no one was permitted to step and recycle them as paving stones for a road.
I can't claim that I approve of this or any act of iconoclasm. But I guess the pagans of Gaza had given the Bishop a tough time, and tough times call for tough men and tough action.