Camp

[Carlton Bach]

Soldiers, milites, were not allowed to wear armor while in the city of Rome

This is something I have heard quoted a lot on the site - is this an actual written law that has survived or is it just an "assumed" custom?

From what I've found it seems there was never a specific law that stated 'no military gear inside the city', but rather a Republican legal tradition that made soldiers inside both impractical and offensive. Basically, a military command (imperium) only applies *outside* the pomerius, the sacral boundary of the city. Once a holder of imperium entered the city, it lapsed. That is also why the centuriate assembly (comitia centuriata) in which the Roman people gather in their traditional military formations take place outside the pomerium and returning generals do not enter the city until their triumph (which had to be specifically approved according to Livy 45,35,4). I know of no legal source preserving the original law (it is likely to be very old), but Cassius Dio notes exceptions to the rule made for various Late Republic strongmen (Pompey, Caesar, Augustus and Tiberius). Augstus' imperium also had to be made pomerium-proof.

Traditionally, soldiers in a triumph would not wear military gear.

Altogether I don't think an individual soldier walking in to see his mother while wearing armour would be arrested for blasphemy, but the Roman tradition frowned on armed formations inside the city. We have evidence (merntions in satirical writing) that soldiers in Rome (praetorians, urbani, vigiles, equites singulares and classiarii - though it's not clear which ones are meant) wore military boots and probably swords, but the mention of 'cohortes togatae' suggests that they were not armoured or in battle gear while on duty.