Consider the Scottish Claymore:
The last known battle in which it is considered to have been used in a significant number was the Battle of Killiecrankie in 1689.[You gotta love that name for a battle]
It was somewhat smaller than other two-handed swords of the era. The average claymore ran about 140 cm (55 in) in overall length, with a 33 cm (13 in) grip, 107 cm (42 in) blade, and a weight of approximately 5.5 lb (2.5 kg).[citation needed]
Try swinging that all day.
It is a great placename.
Some of these battles lasted a long while. Most were over in a couple of hours at the most. Frequently, the main combat lasted under an hour and was decisive, and the rest of the combat consisted of skirmishes between remnants of the defeated force and those sent to round them up / finish them off.
The really large battles didn’t start to take the better part of a day until masses of troops became enormous, a process accelerated by improvements in firearms.
Interesting sidebar, regarding the Battle of Stamford Bridge — the consequences of not wearing one’s armor was clear, but the Norse reinforcements who finally arrived in their armor mostly collapsed from their march weighed down by it, and in the heat that day.
http://en.wikipedia.org/wiki/Battle_of_Stamford_Bridge