A sabre is a sword designed to be used in one hand. It is curved, and the outside edge of the curve is sharp, as is the point and the tip-end of the back edge, but typically most of the back edge, from the hilt to about two thirds of the way up, is blunt. It is a sword type used by cavalrymen. During the musketry days of the Napoleonic Wars, cavalrymen had sabres, whereas infantry officers were issued with swords which were in most respects the same, except that they were straight.
My tulwar. This is a Moghul Indian style of sabre.
I had been led to believe by various things I had read, that the difference between a straight sword and a sabre or scimitar (another type of curved sword, much like a sabre, except usually a bit broader-bladed) was largely cultural and cosmetic - that there was little functional difference. I now believe otherwise.
The Moghul Indians used a type of sabre called a talwar (this has several spellings, including tulwar), which was pretty much identical to a European sabre, except the style of the hilt. I own one of these. Holding it and wielding it has taught me two things.
The first is an answer to a mystery I had observed on a few occasions. Sabre-wielding cavalrymen are often pictured holding their swords in what appears to be an odd way. They charge forwards at the gallop with the sabre thrust forwards in front of them. There's little odd in this, but they hold the sword twisted so that the curve points the tip of the sabre at the ground, and the sharp curve of the edge is on top. One might expect the sharp edge to be on the bottom, and the tip to curve up to the sky, as would be the case if a man had just chopped the sword downwards.
Try this: extend your right arm in front of you, with the palm of your hand facing to the left. Now bend the hand down at the wrist as far as it will go. Next, in this position, grip an imaginary sword, the blade of which would be roughly in line with your arm, reaching out in front of you. This is the position you would be in if you held a sabre edge-down, pointing forwards. Your wrist is as flexed as it can be in that direction. Now imagine the weight of three feet of blade pulling down on that wrist joint, which is already at its furthest extent. Now imagine that you are galloping on a horse across the countryside, with the weight of that blade being jostled up and down with a fair degree of force. Even a gentle up and down movement is uncomfortable. A full-throttle gallop over rough ground would break your wrist.
Conversely, if you now twist your arm around anticlockwise so that the back of your hand is facing to your left, you will now be in the position you would be in if you held the blade edge-up. You can still point the sabre forwards, but now you have quite a bit of flex in your wrist to absorb the weight of the descending blade.
So, that cleared up the mystery for me, I hope it does too for you. One would hold a straight sword the same way, but the problem is more obvious with a curved one.
The second thing I have learned from wielding my talwar is far less trivial. Most wargaming rules systems treat curved one-handed swords as equivalent to straight ones. Runequest for instance treats scimitars and broadswords as pretty much the same. This is, I contend, wrong. Sabres are next to useless for fencing. The curve of the blade makes the whole thing amazingly unwieldy. To hack, and then get the blade back into position for parrying is very difficult and slow. The curve does not make thrusts impossible, but thrusting with a straight sword is much easier.
Remember that these curved weapons were used by cavalrymen. If a cavalryman rides up to an infantryman and stops, and then fences with him, he loses almost all his advantage. Horses are very large and very scary, and the momentum which a moving horse adds to a blow makes a slash from a passing horseman terrible indeed. But if a horseman were to sit and fence, then his horse's head would be in his way, and his horse would offer a huge fleshy target which he could not protect with his parries, and which might buck or bolt at any moment. The rider would only have one angle of attack: downwards. He would find it difficult to fight opponents behind him or to his left, and would find it difficult to attack the lower halves of his foes. The infantrymen could get round him, and attack his immobile legs, his horse's legs, and (especially if he had no shield and used reins, as Napoleonic cavalrymen did) his left arm. He would be in big trouble.
Cavalrymen would ride at infantry, take a hack at them as they passed, and then use their speed to get past and away. Cavalry were good at attacking disordered and routing footmen, but much less good at attacking well-ordered troops, especially if those troops had long weapons such as spears or muskets with long bayonets on them. Against a formed body of infantry, they would rush at them and attack the ends of lines, gaps and weak points, hoping to get round a flank. If the infantry held, the cavalry would ride away and regroup and try again. Often the infantry would break formation, and then the cavalry had a good chance. A mass of cavalry thundering across the battlefield takes a lot of nerve to face. What cavalry did not do, was ride up to the infantry head-on, halt, then try to whittle away the numbers of the enemy by fencing on the spot.
When cavalry met cavalry, they would prefer not to halt to fight, but instead try to use nerve and formation to drive the enemy off, or mill about taking passing hacks at each other, using speed and horsemanship to gain advantage.
Given that this was how cavalry operated, it would make sense to issue them with weapons suitable for the style of fighting. A curved blade is good for slashing. A straight blade may smash into a target, and knock the sword from the swordsman's hand. With a curved blade, the blade is more able to slide across the target, cutting it, and staying in the horseman's hand. At the moment of impact, less of the edge is likely to be in contact with the target, and so greater pressure is exerted on that smaller area.
So, a curved blade is better for slashing with from horseback. It is, however, much worse for other tasks, such as fencing on the spot. Perhaps this was a good thing. Given a straight sword, a horseman might be more inclined to stop and fence. With a weapon useless for this, the horseman will instead behave as his general wants him to: to attack in passing. To stop and fence is to "get it wrong". The design of the sabre makes it unlikely that a rider will get it wrong. An infantryman would be given a straight sword, because he would be expected to have to fight on the spot against his opponents.
Livy, in his description of the Battle of Cannae (216 B.C., Romans 0, Carthaginians 5, away win) wrote:
Soon the Gallic and Spanish horse on the Carthaginian left were engaged with the Roman right. Lack of space made it an unusual cavalry encounter: the antagonists were compelled to charge head-on, front to front; there was no room for flanking manoeuvres, as the river on one side and the massed infantry on the other pinned them in, leaving them no option but to go straight ahead. The horses soon found themselves brought to a halt, jammed close together in the inadequate space, and the riders set about dragging their opponents from the saddle, turning the contest more or less into an infantry battle (Book XXII Chapter 47, Penguin translation).
To me, this clearly indicates that Livy considered the practice of halting to fight to be something cavalry would avoid if they could, and that cavalry would prefer to fight on the move.
Some readers may be familiar with the modern sport of fencing, and with the fencing sabre, which is thin, whippy, and quite wieldy weapon, which can certainly be used for parrying, and is only slightly curved. Such a sporting weapon is very significantly different from the military form of sabre, which has a blade about 11/8" deep. Such a blade has a momentum far more committed to its plane of movement, than the thin square-section fencing sabre, which turns this way and that far more easily.
My tulwar has a hilt that was clearly made for someone with smaller hands than I. The scabbard is wooden, covered with fine leather. When in its scabbard, two prongs of metal on the hilt are outside the scabbard, one either side. I'm not sure what the purpose of these is, but I have been told that they are called langettes and are there to stop rain and dirt getting into the scabbard. They may also be decorative, as they are a bit big for this little job. Just possibly they were to give a warrior some ability to trap an opponent's blade. They do not grip the scabbard enough to stop the sabre falling out. In this picture, you can see a maker's mark on the blunt back of the blade.