Quote Originally Posted by gkathellar View Post
There's also a basic physiological problem — to actually use two long weapons, as opposed to just hold them, you need to keep both of your shoulders forward, and your feet in a position to drive either arm at any given time. For many weapons (though not all), this goes against doctrine. A profile or half-profile presents a narrower, more easily defended target. Placing your feet in a position to drive either hand usually slows defensive footwork. There's a lot of defensive compromise for a limited amount of offensive gain.
You can just square your stance, and have both weapons roughly in range though.

Getting any meaningful swing with both at roughly the same time is however just awkward - one can take a swing in one direction, step onto one leg, shift his body weight etc. in one direction, attempt at two at the same time will be rather counterproductive, from obvious reasons.

I guess that's why people were attempting double rapiers - with weapons of such strictly thrusting dynamics, one could try to make it work.

My understanding is that Florentine duelists usually managed to die in the process of killing their opponent. One can imagine how that wouldn't really catch on.
Case of rapiers was described in manuals from all around the Italy, so this wasn't some very isolated idea.

Probably used mostly by people who were desperate for adrenaline still.