Just a couple of comments on Voobaha's reply.
Peasants would rarely if ever wield crossbows, to my knowledge - the crossbow was a specialised military weapon without a day-to-day application, so even though it was easy to use, it was typically only used by professionals, most famously the Genoese. It could also be used by free yeomen - who would be rich enough to keep their own equipment - eg in the Swiss cantons, I think.
The English longbowmen were not peasants but yeomen, free commoners. This class were required to train heavily in use of the (originally Welsh) longbow and formed the backbone of late-medieval English armies.
Mercenaries - the bulk of medieval mercenaries were actually mounted heavy cavalry, often knights themselves, not much different from regular nobles' retinues. However it's the more unusual infantry forces that stand out in history. The reason for this, as Machiavelli points out, is that mercenary cavalry always have the option of running away if things aren't going well, and frequently did so. Battles between mercenary cavalry units tended to involve a lot of maneuvering and very little actual bloodshed.
By contrast the Swiss infantry pikemen, or German landsknechte pike, had to actually win or die in bloody hand-to-hand combat, making them *much* more useful on the battlefield to their employer.
Peasants would rarely if ever wield crossbows, to my knowledge - the crossbow was a specialised military weapon without a day-to-day application, so even though it was easy to use, it was typically only used by professionals, most famously the Genoese. It could also be used by free yeomen - who would be rich enough to keep their own equipment - eg in the Swiss cantons, I think.
The English longbowmen were not peasants but yeomen, free commoners. This class were required to train heavily in use of the (originally Welsh) longbow and formed the backbone of late-medieval English armies.
Mercenaries - the bulk of medieval mercenaries were actually mounted heavy cavalry, often knights themselves, not much different from regular nobles' retinues. However it's the more unusual infantry forces that stand out in history. The reason for this, as Machiavelli points out, is that mercenary cavalry always have the option of running away if things aren't going well, and frequently did so. Battles between mercenary cavalry units tended to involve a lot of maneuvering and very little actual bloodshed.
By contrast the Swiss infantry pikemen, or German landsknechte pike, had to actually win or die in bloody hand-to-hand combat, making them *much* more useful on the battlefield to their employer.