Originally Posted by
Matthew
With the corollary that we do not really know how the Romans fought, I think I can explain why the pila is generally viewed as the primary weapon of the Roman soldier...
The first thing to bear in mind is that the object on the battlefield is not to kill the enemy in a stand up fight, but convince him to run away. With that in mind, imagine you have 12,000 Roman soldiers on the field. They march up to around 90 feet of the enemy line and then groups of them begin rushing forward in unison and hurling their pila into the enemy line. They can keep doing this until they have hurled 24,000 pila. What the commander is watching for are signs that the enemy formation is breaking up. At that point he orders the charge and the whole Roman line surges onto the enemy, who will hopefully not fight at all, but turn and run away.
This is exactly the same idea that early medieval armies use, except instead of javelin armed footmen, they use combinations of javelin armed horsemen and bow armed foot. Their object is to break up the enemy line sufficiently that it will break when charged by cavalry. The horsemen themselves have either a javelin or lance as their primary weapon, but when the real killing begins it will be swords, just like the Romans before them.