I understood that driving on the left was to keep the whip hand (right hand for most ppl) more available in case the horse on the opposite side drifted over into your lane; with your whip on that side, you could divert the horse back into its proper lane.

In areas with no pavements ("sidewalks" for Americans) in Britain, ppl still walk on the right-hand side of the road to face oncoming traffic, so you know what's coming and can dive out of the way if required.

IanC, certainly that's the origin of "starboard". But I believe steering oars had long since vanished by the time Britain became a major seafaring nation (Henry 8th kind of era).

Another interesting one for you - most spiral staircases, at least in older buildings, go up clockwise. If your castle was attacked and you were backing up a tower, your right hand was free to attack the person coming up, whereas his right hand would be blocked by the central pillar. I seem to remember hearing that one king/prince/lord actually assembled a group of left-handed soldiers specifically for attacking castle towers.

If you're right-handed, the sword will always be slung on your left side so that you can draw it across your body. This allows your hand to cover a distance twice the length of your arm, which is sufficient to draw most swords (and if it was bigger than that you probably couldn't lift it!) and it's a strong, natural movement. There is no way of drawing a sword (at least if it's bigger than a large knife) with your right hand if it's hung on your right-hand side. The maximum distance your hand can cover then is just the length of your arm (swords would often be longer than this), and it's quite a weak and awkward movement.

Finally, there's the custom of the left hand being the "dirty" hand, since that's the hand you wipe your bottom with - you eat (and shake hands) with your right hand. This is still the case in Middle Eastern and other poorer countries.

Graham.