Late Roman belt

[markusaurelius]

But then I firmly believe that the norm was not to wear any belt except the sword belt over armour, and certainly not the wide belt set with all your day-to-day crud hanging off it.

Well the mosaic that Robert posted shows the wide belt with the armor, and really if I was going into battle I would want my knife attached to my belt for obvious reasons. Where would you hang it, if it wasn't attached to your belt?

There's an old re-enactor fallacy that wearing a belt somehow helps to relieve the weight of a mail shirt but it's exactly that, a fallacy...unless somebody's invented a magic anti-gravity belt that I'm not aware of.

I'm not sure why you think that. A modern hikers backpack has waist "belts" for that very reason. If you have a belt at the waist, it basically holds everything under it up off of your hips, essentially "relieving" the weight off of your shoulders (as it is now supported by the hips). This helps spread the weight out and make it less tiresome on the shoulders. No anti-gravity required.