Despite frequent claims to the contrary, Medieval swords were indeed light, manageable, and on average weighed less than four pounds. As leading sword expert Ewart Oakeshott unequivocally stated: "Medieval Swords are neither unwieldably heavy nor all alike - the average weight of any one of normal size is between 2.5 lb. and 3.5 lbs. Even the big hand-and-a-half 'war' swords rarely weigh more than 4.5 lbs. Such weights, to men who were trained to use the sword from the age of seven (and who had to be tough specimens to survive that age) , were by no means too great to be practical."
Crazy. Although it makes sense to use a light weapon if you can, I didn't think the technologies of the time would have allowed for such light weight while retaining strength, considering you had to deal with armor. Interesting piece, check it out.