Clydesdale's are a rough approx of the medieval knights charger but travel was on palfreys
Many people don't realise how large a cavalcade a knight can require. One knight (or, depending on period, man at arms) might have a palfrey to ride when not killing people, possibly a remount for when the palfrey gets tired, a warhorse to ride when killing people, a pack horse to carry his armour (since most of the time he isn't wearing it), if he has a squire that's another horse or several, and if he needs to carry e.g. fodder...
--
David