There were four medieval army ranks. They are as follows:
- Knights
- Mercenaries for Hire
- Soldiers
- Servants who would do the work of camp followers and servants
A knight is thought to have been typically better off than a mercenary for hire, because he was also bound by his oath of fealty to serve the lord. In other words, that form of service required an investment of time in training and experience before they even got out into battle; mercenaries just fought whoever physically came at them on the battlefield.
A soldier was a common enough soldier in any assortment of armies – but it’s not clear where they ranked with regards to knights versus mercs or servants.