Rain Miracle in June

Wikipedia is host to many bizarre and spurious claims, which I suppose is only to be expected in a publicly editable resource.

In my own field of ancient history, many of the errors are common misconceptions and some are the pet theories of cranks who don’t like the communis opinio, but some have a far stranger origin. Take, for example, the case of the “rain miracle” on the Column of Marcus Aurelius in Rome. Wikipedia informs us that it occurred on this day; namely, 11 June.

The context is the Marcomannic Wars fought by the emperor Marcus Aurelius on the Upper Danube frontier in the early AD 170s. The Roman historian Cassius Dio (or rather, his eleventh-century epitomator, John Xiphilinus) recorded an incident from a later phase of the war, when the Romans were fighting the tribe of the Quadi. On this particular occasion, the Romans were surrounded and in danger of succumbing to heat and thirst.

“The Romans, accordingly, were in a terrible plight from fatigue, wounds, the heat of the sun, and thirst, and so could neither fight nor retreat, but were standing in the line and at their several posts, scorched by the heat, when suddenly many clouds gathered and a mighty rain, not without divine interposition, burst upon them” (Roman History 72 (71).8.3).

Xiphilinus himself was amazed by the story, which he explained by claiming that the Roman force involved was the Twelfth Fulminata Legion (whose name means “thunder-bolt bearers”), and furthermore that the soldiers were well-known Christians, whom the emperor implored to pray to their God for salvation. “Their God immediately gave ear and smote the enemy with a thunderbolt and comforted the Romans with a shower of rain” (Roman History 72 (71).9.5).

However, no date was attached to the tale; not even the year, although it can most probably be placed in AD 172. Incidentally, the Christian element, introduced here by Xiphilinus himself, was already known to the Christian writer Tertullian in AD 200, around the time that Cassius Dio was writing. Be that as it may. My question here is: where on earth did Wikipedia’s date of 11 June come from?

The answer is rather convoluted, as it turns out. A series of fragmentary altars discovered at the Roman fortress of Carnuntum (where Marcus Aurelius had his headquarters during the Marcomannic Wars) all made reference to some unnamed event that had occurred on III Idus Iunias (“the third day before the Ides of June”). By Roman calendrical reckoning, the Ides of June fell on the 13th, and the third day before (using inclusive counting) was 11 June.

It was the German archaeologist Werner Jobst who claimed, firstly, that the earliest such altar could be dated to AD 172, and secondly, that the event thus commemorated on all the altars must have been the “rain miracle”.

Unfortunately, this inscription that Jobst wanted to have been erected on 11 June AD 172 (AE 1982, 778, pictured here) turns out to have been erected in AD 159. And so the case for a “rain miracle” on 11 June AD 172 crumbles. Or, more appropriately, is washed away.