Swordsmen and spears are way so different.

[Watchman]

By what I know of it the damn horses actually tended to pull short rather than smash into what to them appeared like a large, solid, immobile obstacle. The critters are very picky about footing, and can apparently reduce speed surprisingly rapidly.

Anyway, AFAIK the infantrymen would tend to survive the impact of even heavy warhorse pretty well if they were in proper formation and "braced for impact". It's not like even a fully barded large warhorse is equivalent to a car or similar; the collision would of course push the front ranks back, but as they were being pushed into something relatively yielding (ie. the men behind them) by something relatively yielding (ie. a big animal) actual injuries would be fairly minor. Nasty bruises and some broken bones, naturally, but I for one consider those *far* lesser an evil than what happens if you fall down and get trod over by the big beast, or get hit by its rider's choice tool of personal destruction.

I sincerely doubt if the impact of a horse could actually shatter a shield, too. A solid hit from a decent mace or axe would reduce a shield to splinters in one go, but that's because the things concentrate the impact; a charging horse is, ultimately, no more "concentrated" than for example a football quarterback.

Which is of course why cavalrymen so long ago figured out it'd be a really nice thing if all that momentum could be concentrated behind somehting, like a long pointy stick... Works both ways, though. A horse or its rider that hits the tip of a properly "set" polearm (ie. braced on the ground, the tip usually at the level of the horse's chest) on a charge will be impacting with the same full momentum that goes behind a lance tip, and tends to get duly skewered. (Armour helps a bit as usual, though.)

Which is another reason why spears and other polearms were so popular; not only do they have enough reach to negate the height advantage of a cavalryman (or the reach advantage of another similar weapon), they could be used to turn one of the horse's greatest assets against itself.

However, even infantry without long and pointy things has time and again demonstrated it can check a heavy cavalry charge if it keeps it nerve and deploys in a suitable formation; that Roman legionaires with their javelins and short swords indeed could take on Persian cataphracts is a good example, although I understand in that particular case they tended to have a rather hard time at it...

[Red Harvest]

Where the sword comes into play is once you get inside that spear tip's effective range, primarily thrusting swords. The spear is a stand off weapon. Once the swordsman has closed, he has the advantage.

Modern day analogy: boxer versus a slugger. The slugger tends to be heavily muscled and dangerous at close range. A good boxer will tear a slugger to pieces from the outside. The match is one of the slugger trying to penetrate past the jab and deliver punishing blows, while the boxer works the jab to maintain a distance. This doesn't mean that the slugger is unskilled, but his reach tends to be shorter so he has to fight differently.

The swordsman will also have an advantage in woods, halls, etc. where the spear's length will make it more difficult to wield due to obstructions, and formation fighting for spearmen becomes quite difficult.

[m52nickerson]

I disagree. A spearman only needs room to the front of him to jab forwards with the spear. A swordsman needs room all around to swing and recover the sword properly. This is why spears are much more effective in groups. Now if you are talking about swinging a spear, its not really a spear, but a quarter staff.

[Alexanderofmacedon]

Cavalry can't throw themselves on swords like they can on spears...

[Red Harvest]

I disagree. A spearman only needs room to the front of him to jab forwards with the spear. A swordsman needs room all around to swing and recover the sword properly. This is why spears are much more effective in groups. Now if you are talking about swinging a spear, its not really a spear, but a quarter staff.

Nope, any time you have something 6 ft long or more, you are going to have trouble wielding it with obstructions compared to something 2 or 3 feet long. Back to a wall, the spearman is in big trouble being limited to parrying, the swordsman can still thrust and cut. Remember, swords like the gladius are thrusting weapons too. If you are talking about a pike 9 feet or longer then just turning it in the woods becomes a big challenge. It's analagous to the trouble a long rifle has versus short barreled weapons in confined spaces/close quarters.

That was a weakness of phalanx formations, They were deadly straight ahead, but if disrupted by vegetation or terrain, they were not sufficiently flexible.

And regardless, once the swordsman gets past the spear tip he is on offense, while the spearman is on defense.

[m52nickerson]

Nope, any time you have something 6 ft long or more, you are going to have trouble wielding it with obstructions compared to something 2 or 3 feet long. Back to a wall, the spearman is in big trouble being limited to parrying, the swordsman can still thrust and cut. Remember, swords like the gladius are thrusting weapons too. If you are talking about a pike 9 feet or longer then just turning it in the woods becomes a big challenge. It's analagous to the trouble a long rifle has versus short barreled weapons in confined spaces/close quarters.

That was a weakness of phalanx formations, They were deadly straight ahead, but if disrupted by vegetation or terrain, they were not sufficiently flexible.

And regardless, once the swordsman gets past the spear tip he is on offense, while the spearman is on defense.

A gladius, like all short swords is primarily a thrusting weapon. They how ever however ineffective verses a spear formation. Even if the swordman armed with a short sword got past the first row of spear heads he sill had to get close enough to kill with that short sword. He ran into the problem of the second and third row of spear heads. That is why in Roman times and earlier the phalanx was so effective.
Later on with the development of larger swords, long swords, bastard sword, two handed swords. They were more effective. The swordman no longer had to get so close to kill. They could get inside the reach of the first spear row, and fend off the second with a shield while killing the first row of men. The larger slashing swords could also break spears.
So this left the spear useful for defending against calvary, but not against infantry.
Also remember this, as spear may be twice as long as a sword, but you don't hold a spear at its very end. You do a sword. So the spears over all length is not always used.

[Red Harvest]

A gladius, like all short swords is primarily a thrusting weapon. They how ever however ineffective verses a spear formation. Even if the swordman armed with a short sword got past the first row of spear heads he sill had to get close enough to kill with that short sword. He ran into the problem of the second and third row of spear heads. That is why in Roman times and earlier the phalanx was so effective.
Later on with the development of larger swords, long swords, bastard sword, two handed swords. They were more effective. The swordman no longer had to get so close to kill. They could get inside the reach of the first spear row, and fend off the second with a shield while killing the first row of men. The larger slashing swords could also break spears.
So this left the spear useful for defending against calvary, but not against infantry.

Huh? The gladius was superior *because* it was a short thrusting weapon, and was ideal for this close in work versus spears. Not that spears were easy to penetrate, that is what the armour and shield were for--to get inside to do the work. Once inside a shorter weapon was superior. A long sword won't compete with a 14+ ft sarissa.

The gladius grew shorter for a time, rather than longer, then eventually the legions transferred to the spatha, but by then they were no longer facing the Greek or Macedonian style phalanx. I've not studied this later time period, but I suppose it was more of using the traditional weapons of non-Roman populations who now composed the legions.

You are now getting more into the formation vs. single man debate and mixing elements. The phalanx lost in this, because of its inflexibility. It was superior head to head, as long as it could maintain cohesion. However, facing more heavily armoured enemies, it could no longer be relied upon to keep swordsmen at bay, and the cohesion could be lost more easily. (As you armour up both sides, the relative effectiveness of the phalanx falls.) Additionally, the pila served to break up the phalanx before melee started.

Unless I've completely misread history, it was the gladius that was part of the system that made the phalanx ineffective, not longer swords.

Also remember this, as spear may be twice as long as a sword, but you don't hold a spear at its very end. You do a sword. So the spears over all length is not always used.

Of course, that's what I was trying to tell you when you said that the spearmen only had to worry about the front. That is also why you have more trouble with spear in a confined area. Try carrying a 9 ft long shaft through the woods and make a few turns and maneuvers. Unless you are in a very open forest you are going to have some serious problems.

[m52nickerson]

A long sword won't compete with a 14+ ft sarissa.

If you are implying that one-on-one someone armed with a 14 ft spear, could beat someone with a long sword (all things being equal), you are dead wrong.

Yes the Gladius did help bring down the phalanx, reading my post again, I gave the wrong impression. Spear formation did continue thou. As armor was improved the Gladius slowly became less effective vs armored spear troops. Were larger swords started to come into there own.

[ajaxfetish]

I disagree. A spearman only needs room to the front of him to jab forwards with the spear. A swordsman needs room all around to swing and recover the sword properly. This is why spears are much more effective in groups. Now if you are talking about swinging a spear, its not really a spear, but a quarter staff.

It's been mentioned that swords are most effective in close, tight combat. The most common swords would be short swords, which didn't need room all around to be swung and recovered as they were mostly for close-quarters thrusting. And of course they had the additional advantage of being much cheaper and easier to make than the longer varieties.

They would also be lightweight, so they could be thrust, retracted, and occasionally swung quickly and comparatively easily. So in close the sword would have the advantage.

Claymores ranged from 5lb to 15 lb.

While some swords may have been up to 15 pounds they would be exceptional, expensive, and unwieldly and would require two hands to use effectively. So 5 kilos (about 11 pounds, on the heavy side even for a claymore) would be possible but uncommon and not a weapon for the average man to use along with a shield.

Ajax

[Kraxis]

Narayanese... I'm not certain what you mean by lance. If it is the cavalry weapon where it tapers into a small point, then it is logical that it is expensive. But a normal spear of a leafpoint (or similar) and a small buttspike would be something even a poor farmer would be able to obtain fairly easily. In fact it was common to see Danish farmers bring spear and shield onto the fields as protection from whatever.

The problem with spearless infantry is that they get struck first. Not only does the cavalryman know this, but more importantly the infantryman knows this. He will not like it at all... Imagine him thinking "If I say we will win, but I die. If I run I might live." Only the most hardcore infantry would stand their ground.
While Parthian cataphracts were good, they were also fairly primitive (bear with me). The shock cavalry training wasn't too advanced yet. Not to say that shock cavalry didn't exist, but they were used against other cavalry, so they could get behind the infantry. When facing infantry head on they would face the problem of the natural inhibition of the horse for running into seemingly solid objects, such as two high shield wall of scuta. The horse wouldn't know that it could actually run through it and would stop just like it would with a stone wall.
On the other hand Seleucid cataphracts did break through a dense, and quite good, formation of legionaries (mind you these were of Polybian setup, but perhaps some of the best of this type) at Magnesia. So it wasn't set that even good infantry could repel heavy cavalry. Part of the reason could be that the Polybian legion didn't have the special two-shield wall of the Marian legion, thus it didn't present a seemingly solid wall, but more one of humans.

In the medieval period the cavalry slowly climbed the ladder, until they were the top dogs and the knights entered the field. Naturally these were keen to find ways to defeat infantry, though they still preferred to beat the other side's cavalry first.
It was 'discovered' (as if people didn't know this before) that horses are blind until about 1-2 meters directly ahead of its face. This is part of the horse's inhibition against running into stuff. Try yourself to run into stuff if it vanishes right before you hit it, it is not pleasant. But a system was developed to counter this, where the horse was ridden against human figures in fairly dense formation and when close enough to be 'hidden' they were dropped or similarly removed. After extensive training the horse would be comfortable with it's owner's directions, even against infantry.
Knight could, and would, attack infantry head on. Sometimes they won, sometimes they didn't. Sometimes the infantry stood and lost (such as the Bouvines), sometimes they stood and won (Bannockburn and Courtrai), and often the infantry broke and ran prior to impact.

If the infantry stood it would still not be good to be in the front lines even if you are not struck directly. The impact of the horse itself would at least knock you to the ground, and if you were unlucky it would knock you out (air blasted from lungs or heavy hit to the head). Surviveable? Yes, but then comes the next few horses, and these horses are not nice skittish ones, they don't mind stepping on you. Ouch... But even if the charge is broken you are in a world of pain as the horses around you get killed and fall to the ground, or get wounded and thrash around in pain stepping on whoever happens to be lying on the ground. An given you are most likely not equipped with superior armour you will get rather badly injured if not killed outright.
Suddenly even a successful stand against knights looks bleak for those in the first line, and those on the second fares pretty much the same.
Ducking down behind the shield will not be enough...

So I think it is fair to say it is understandable that infantry would run more often than not.