Trousers did not really become an item of Western men's wear until the nineteenth century.
An argument can be made for breeches, which became a thing in the seventeenth century. Also sailor's trousers in the eighteenth. It's still a long way from ancient Rome.
Many modern "historical" costumes include trousers, apparently because modern men are squicked out by wearing what are really rather aggressively "not-trousers." But trousers are not authentic for western menswear before the nineteenth century.
Thought those hideous pantaloon thingies men wore in the renaissance were called "slops," at least in the UK. But maybe that's a modern term.
According to etymology online (which is certainly not always accurate), the word breeches dates back to the 12c from Old English. Thought Anglo Saxon guys wore something resembling trousers for a while.
I thought male peasants, at least, wore tunics (with linen undershirts) and breeches (often leather) even back in the middle ages, at least in some parts of Europe. I've seen pictures of medieval peasants (males) wearing different sorts of outfits. Of course, searching tonight, I'm not finding pictures that actually originated in the middle ages--they all seem to be people dressed in "period" costume.
This is the only one I could find quickly that shows a variety of medieval outfits:
http://en.wikipedia.org/wiki/File:Crescenzi_calendar.jpg
Hard to tell if the leg coverings are all stockings, really, or some are more along the lines of breeches.
But I could swear I've seen historic pictures of men working out in the fields wearing things that looked more or less like loose fitting pants, instead of tightly woven stockings. I've seen pictures of them wearing just shirts and tunics and going bare legged too, though, like Romans.
Wouldn't it be too cold to go around in just a tunic, with bare legs, in northern Europe at least?
And I thought I read somewhere (may have been one of the museums up along Hadrian's wall when I visited) that the Roman soldiers in Britain reluctantly adopted something that resembled pants, though. Again, it got a bit cold there for them to go bare-legged year round.
And sorry--I feel guilty now for derailing this thread by bringing up the idea of men needing to wear dresses to protect their willies from getting pinched. I just had a really hideous image in my mind of Ted Beale in a Roman tunic with rabbit ears.
Eeeeewwww!
